SECURITIES PURCHASE AND FACILITIES AGREEMENT


                                 by and between


                                    CSP INC.


                                       and


                               VERTICALBUYER, INC.



<PAGE>

                                    AGREEMENT

     AGREEMENT (this "Agreement" is dated as of March 2, 2000 by and between CSP
Inc., a Massachusetts  corporation ("CSPI", and VerticalBuyer,  Inc., a Delaware
corporation ("VerticalBuyer").

     WHEREAS,  CSPI is a  publicly-traded  company the common  stock of which is
traded on the National  Market System of the National  Association of Securities
Dealers Automatic Quotation Market ("NASDAQNM") and

     WHEREAS, business and financial information concerning CSPI is available on
the Electronic Data Gathering,  Analysis and Retrieval System (known as "EDGAR")
maintained by the United States  Securities and Exchange  Commission  ("SEC") on
its World Wide Web site, www.sec.gov; and

     WHEREAS,  VerticalBuyer  is a  private  Delaware  corporation  which is the
holding  company and parent of its  wholly-owned  subsidiary,  a United  Kingdom
company, Lightseek, Limited ("Lightseek"); and

     WHEREAS,  CSPI desires to purchase an aggregate of 5,000,000  shares of the
common  stock,  $.001 par value each) of  VerticalBuyer  ("VerticalBuyer  Common
Stock"), at $1.00 per share, representing, after the purchase, 25% of the issued
and outstanding shares of VerticalBuyer  Common Stock and VerticalBuyer  desires
to sell to CSPI  5,000,000  shares of  VerticalBuyer  Common  Stock,  ("Shares")
subject to the terms and conditions hereinafter set forth; and

     WHEREAS,  CSPI desires to assist in the  establishment  of  VerticalBuyer's
United States office through provision of office space,  computer facilities and
related  personnel  and services and by the provision of members of its board of
directors on the board of directors and committees of the of  VerticalBuyer  and
VerticalBuyer desire the assistance of CSPI pursuant to the terms and conditions
hereafter set forth; and

     WHEREAS, CSPI and VerticalBuyer are executing and delivering this Agreement
in reliance  upon the exemption  from  securities  registration  afforded by the
provisions of Regulation D ("Regulation D"), as promulgated by the SEC under the
1933 act of 1933, as amended (the "1933 Act"); and

     WHEREAS,   contemporaneously  with  the  execution  and  delivery  of  this
Agreement,  the Parties are  executing  and  delivering  a  registration  rights
agreement  pursuant  to  which  VerticalBuyer  has  agreed  to  provide  certain
registration rights under the 1933 act and the rules and regulations promulgated
thereunder,  a voting agreement among the majority stockholders of VerticalBuyer
and CSPI and three warrants, all in the forms attached hereto as Exhibit 2.02.

     NOW THEREFORE, in consideration of the premises and the covenants set forth
herein, the parties hereto (the "Parties" and,  individually,  a "Party") hereby
agree as follows:

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<PAGE>

                                    ARTICLE 1
              PURCHASE AND SALE OF SECURITIES - FACILITIES PROVIDED

1.01 Purchase and Sale.

     (a)  Subject to the terms and  conditions  of this  Agreement,  CSPI hereby
          purchases and VerticalBuyer  hereby sells to CSPI 2,000,000 Shares and
          three redeemable  common stock purchase warrants (the "Warrants") each
          warrant containing the right to purchase 1,000,000 Shares at $1.00 for
          a period  of two  years  from the  date of an  effective  registration
          statement  relating to the  underlying  Shares.  The three  classes of
          Warrant are  redeemable  upon thirty days' written  notice as follows:
          Class "A", upon the effectiveness of a registration statement relating
          to the underlying shares of VerticalBuyer  Common Stock; Class "B", in
          the event the closing  price of the Shares on  VerticalBuyer's  public
          trading  market  exceeds $2.00 for a period of twenty (20)  continuous
          trading  days;  and Class "C", in the event the  closing  price of the
          Shares on VerticalBuyer's trading market exceeds $3.00 for a period of
          twenty (20) continuous trading days. In the event the closing price of
          the Shares on VerticalBuyer's public trading market exceeds $3.00, the
          time  period for  redemption  of the Class "B" and Class "C"  Warrants
          will run concurrently.

     (b)  In addition,  VerticalBuyer agrees to issue and sell 75,000 additional
          Class "B" Warrants to holders of existing CSPI options whose names and
          addresses are listed on Schedule 1.01 at a price of $.01 per Class "B"
          Warrant.  These  Warrants  will be included  in the same  registration
          statement to be filed with the SEC relating to the Shares purchased by
          CSPI and the Shares underlying the Warrants purchased by CSPI.

     (c)  The  number  and  exercise  price of the  Warrants  shall be  adjusted
          appropriately  in the event of an  acquisition,  stock split,  sale of
          stock at prices  less than the  market  price of the Shares or similar
          transaction  pursuant to paragraph 7 of the Warrant to be entered into
          simultaneously with this Agreement.

1.02 Purchase  Price.  The  purchase  price  of the  2,000,000  Shares  and  the
     3,000,000 Warrants pursuant to paragraph 1.01 above is $2,000,000.

1.03 Exemption  from  Registration.  Certificates  representing  the  shares  of
     VerticalBuyer  Common Stock issued to CSPI shall bear a restrictive  legend
     setting  forth that the shares  were  issued in a  transaction  exempt from
     registration  under the Securities Act of 1933, as amended (the "1933 Act")
     and may not be transferred unless pursuant to an effectiveness registration
     statement filed with the SEC or an exemption therefrom.

1.04 Registration  Statement.  VerticalBuyer will file a registration  statement
     relating to the Shares issued to CSPI,  the Warrants  issued to CSPI and to
     stockholders of CSPI and the Shares  underlying the Warrants  pursuant to a
     registration  rights agreement (the "Registration  Rights Agreement") to be
     signed by the Parties at or prior to the Closing.

1.05 Facilities  Provision.  CSPI shall provide from the date of the Closing use
     of  office  space  in  its  headquarters  office,  consultation  and  other
     facilities as set forth in a memorandum of understanding attached hereto as
     Exhibit 1.05.

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<PAGE>

                                   ARTICLE 2
                                    CLOSING

2.01 The Closing.  The  transactions  contemplated  by this  Agreement  shall be
     completed  simultaneously or prior to the execution of this Agreement.  The
     Closing  shall  take  place  at the  offices  of CSPI or at  another  place
     mutually  agreed  upon  by  the  Parties.  The  "Closing"  shall  mean  the
     deliveries to be made by the Parties at the Closing in accordance with this
     Agreement.

2.02 Deliveries by VerticalBuyer. At the Closing, VerticalBuyer shall deliver to
     CSPI Share  certificates,  and the Warrants all duly and properly executed,
     representing  the  Shares  and  Warrants  purchased  by  CSPI  pursuant  to
     paragraph 1.01(a).  If not previously  delivered,  VerticalBuyer shall also
     deliver to CSPI at the Closing the documents specified in Exhibit 2.02.

2.03 Deliveries by CSPI. At the Closing,  CSPI shall deliver a certified or bank
     check in the amount of $2,000,000 to the order of "VerticalBuyer, Inc."

2.04 Further  Assurances.  At or after the  Closing,  each Party shall  prepare,
     execute,  and  deliver,  such  further  instruments  of  conveyance,  sale,
     assignment,  or transfer, and shall take or cause to be taken such other or
     further action, as any Party shall reasonably request of any other Party at
     any time or from time to time in order to consummate,  in any other manner,
     the terms and provisions of this Agreement,  including  opinions of counsel
     for each Party relating to the  representations and warranties set forth in
     this Agreement.

                                    ARTICLE 3
                 REPRESENTATIONS AND WARRANTIES OF VERTICALBUYER

     In this Agreement,  any reference to any event, change, condition or effect
being  "material"  with  respect  to any entity or group of  entities  means any
material event, change,  condition or effect related to the financial condition,
properties,  assets  (including  intangible  assets),   liabilities,   business,
operations or results of operations of such entity or group of entities. In this
Agreement,  any  reference  to a "Material  Adverse  Effect" with respect to any
entity or group of entities means any event, change or effect that is materially
adverse to the financial condition,  properties, assets, liabilities,  business,
operations  or results of  operations  of such entity.  In this  Agreement,  any
reference to a Party's  "knowledge"  means such Party's actual  knowledge  after
reasonable  inquiry of  officers,  directors  and other  employees of such Party
reasonably believed to have knowledge of such matters.  VerticalBuyer represents
and warrants to CSPI as follows:

3.01 Organization,   Standing  and  Power.   VerticalBuyer   and  Lightseek  are
     corporations  duly organized,  validly  existing and in good standing under
     the laws of Delaware and the United  Kingdom,  respectively.  VerticalBuyer
     and Lightseek have the corporate power to own their properties and to carry
     on their  business as now being  conducted  and as proposed to be conducted
     and are duly  qualified  to do  business  and are in good  standing in each
     jurisdiction  in which the failure to be so qualified  and in good standing
     would have a Material  Adverse Effect on  VerticalBuyer or Lightseek as the
     case may be.  VerticalBuyer  has  delivered a true and correct  copy of its
     certificate of incorporation, certificate of amendment, certificate of good
     standing and by-laws or other charter  documents,  as applicable,  to CSPI.
     Neither  VerticalBuyer  nor  Lightseek  is  in  violation  of  any  of  the
     provisions of its  respective  certificate  of  incorporation  or bylaws or
     equivalent  organizational  documents.   VerticalBuyer  has  no  direct  or
     indirect majority-owned subsidiaries other than Lightseek.

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<PAGE>

3.02 Authority. VerticalBuyer has all requisite corporate power and authority to
     enter into this Agreement and to consummate the  transactions  contemplated
     hereby.  The execution and delivery of this Agreement and the  consummation
     of the  transactions  contemplated  hereby have been duly authorized by all
     necessary corporate action on the part of VerticalBuyer. This Agreement has
     been duly executed and delivered by VerticalBuyer and constitutes the valid
     and binding obligation of VerticalBuyer  enforceable against  VerticalBuyer
     in  accordance  with its  terms,  except  that such  enforceability  may be
     limited  by  bankruptcy,  insolvency,  moratorium  or  other  similar  laws
     affecting or relating to  creditors'  rights  generally,  and is subject to
     general  principles of equity. The execution and delivery of this Agreement
     by  VerticalBuyer  does  not,  and  the  consummation  of the  transactions
     contemplated hereby will not, conflict with, or result in any violation of,
     or default  under (with or without  notice or lapse of time,  or both),  or
     give rise to a right of  termination,  cancellation  or acceleration of any
     material obligation or loss of any material benefit under (i) any provision
     of the certificate of incorporation or bylaws of VerticalBuyer, or (ii) any
     mortgage,  indenture,  lease,  contract or other  agreement or  instrument,
     permit, concession,  franchise,  license, judgment, order, decree, statute,
     law,  ordinance,  rule or regulation  applicable to VerticalBuyer or any of
     its properties or assets. No consent,  approval, order or authorization of,
     or  registration,  declaration  or filing with,  any court,  administrative
     agency or commission  or other  governmental  authority or  instrumentality
     ("Governmental  Entity") is required by or with respect to VerticalBuyer or
     Lightseek in connection  with the execution and delivery of this  Agreement
     or the consummation of the transactions contemplated hereby, except for (i)
     such   consents,   approvals,   orders,   authorizations,    registrations,
     declarations  and  filings  as  may  be  required  under  applicable  state
     securities  laws and the securities laws of any foreign  country,  and (ii)
     such other consents,  authorizations,  filings, approvals and registrations
     which, if not obtained or made, would not have a Material Adverse Effect on
     VerticalBuyer  and/or and would not prevent,  or materially  alter or delay
     any of the transactions contemplated by this Agreement.

3.03 Financial  Statements.  VerticalBuyer  has  delivered to CSPI the financial
     statements  for the fiscal period ended  November 30, 1999 (the  "Financial
     Statements")  of  Lightseek.  The  Financial  Statements  are  complete and
     correct in all  material  respects  and were  prepared in  accordance  with
     generally  accepted  accounting  principles  applicable  to United  Kingdom
     corporations,   applied  on  a  consistent  basis  throughout  the  periods
     indicated and with each other. The Financial Statements  accurately set out
     and describe in all material respects the financial condition and operating
     results as of the dates, and for the periods, indicated therein, subject to
     normal year-end adjustments. VerticalBuyer will maintain and Lightseek will
     continue  to  maintain  a standard  system of  accounting  established  and
     administered in accordance with generally accepted accounting principles.

3.04 Absence  of Certain  Changes.  Since  November  30,  1999,  the date of the
     Financial   Statements,   except  as   otherwise   disclosed   in  writing,
     VerticalBuyer  represents  that Lightseek has conducted its business in the
     ordinary course  consistent with past practice and that  VerticalBuyer  has
     been an inactive company except for the issuance of Shares to the owners of
     Lightseek and Shares and common stock purchase warrants certain consultants
     and that, as to VerticalBuyer  and Lightseek,  there has not occurred:  (i)
     any change, event or condition that has resulted in, or might reasonably be
     expected to result in, a Material  Adverse  Effect;  (ii) any  acquisition,
     sale or transfer of any material asset other than in the ordinary course of
     business and consistent  with past practice;  (iii) any material  change in
     accounting  methods or practices  (including any change in  depreciation or


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<PAGE>

     amortization  policies or rates);  (iv) any declaration,  setting aside, or
     payment  of a dividend  or other  distribution,  or any direct or  indirect
     redemption,  purchase or other  acquisition  of any shares of capital stock
     except as disclosed to CSPI; (v) any material  contract  entered into other
     than in the ordinary course of business,  and or any material  amendment or
     termination  of,  or  default  under,  any  material  contract;   (vi)  any
     undisclosed material amendment or change to the incorporation  documents or
     bylaws;  (vii) any  increase  in or  modification  of the  compensation  or
     benefits  payable or to become payable to any directors or employees  other
     than in the ordinary  course of business and consistent  with past practice
     or (viii) any negotiation or agreement to do any of the things described in
     the preceding  clauses (i) through (vii) (other than negotiations with CSPI
     and its  representatives  regarding the  transactions  contemplated by this
     Agreement or as otherwise disclosed to CSPI).

3.05 Absence of Undisclosed Liabilities. Neither VerticalBuyer nor Lightseek has
     any  material   obligations  or  liabilities  of  any  nature  (matured  or
     unmatured,  fixed  or  contingent)  other  than  (i)  those  set  forth  or
     adequately provided for in the Financial Statements; (ii) those incurred in
     the  ordinary  course of business  and not  required to be set forth in the
     Financial Statements under generally accepted accounting principles;  (iii)
     those  incurred  in the  ordinary  course of business  since the  Financial
     Statements  and consistent  with past practice;  and (iv) those incurred in
     connection with the execution of this Agreement.

3.06 Litigation.  There is no private or governmental action, suit,  proceeding,
     claim,  arbitration or  investigation  pending before any agency,  court or
     tribunal,  foreign or  domestic,  or, to the  knowledge  of  VerticalBuyer,
     threatened  against  either  VerticalBuyer  or  Lightseek  or any of  their
     properties  or any of their  respective  officers  or  directors  (in their
     capacities  as  such)  that,  individually  or  in  the  aggregate,   could
     reasonably be expected to have a Material  Adverse Effect on  VerticalBuyer
     or Lightseek  except as has been previously  disclosed to CSPI. There is no
     judgment,  decree or order against  VerticalBuyer or Lightseek,  or, to the
     knowledge  of  VerticalBuyer,  any of its  directors  or officers (in their
     capacities as such),  that could prevent,  enjoin,  or materially  alter or
     delay any of the transactions contemplated by this Agreement, or that could
     reasonably be expected to have a Material Adverse Effect on VerticalBuyer.

3.07 Restrictions  on  Business  Activities.  There is no  agreement,  judgment,
     injunction, order or decree against either VerticalBuyer or Lightseek which
     has or could  reasonably be expected to have the effect of  prohibiting  or
     materially   impairing  any  current  or  future  business  practice,   any
     acquisition  of property or the conduct of business as currently  conducted
     or as proposed to be conducted.

3.08 Governmental Authorization.  VerticalBuyer and Lightseek have obtained each
     federal,  state, county, local or foreign  governmental  consent,  license,
     permit, grant, or other authorization of a Governmental Entity (i) pursuant
     to which either of them currently  operates or holds any interest in any of
     its  properties  or (ii) that is required for their  operation,  and all of
     such authorizations are in full force and effect,  except where the failure
     to obtain or have any such authorizations  could not reasonably be expected
     to have a Material Adverse Effect on either VerticalBuyer or Lightseek.

3.09 Title to Property.  Lightseek has good and  marketable  title to all of its
     respective  properties,  interests  in  properties  and  assets,  real  and
     personal,  reflected  in the  Financial  Statements  or acquired  after the
     Financial Statements. The property and equipment of Lightseek that are used
     in the operations of its  businesses  are in all material  respects in good
     operating condition and repair, ordinary wear and tear excepted.

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<PAGE>

3.10 Intellectual Property.

     (a)  Lightseek  owns  or  is  licensed  or  otherwise   possesses   legally
          enforceable rights to use all trademarks,  trade names, service marks,
          copyrights,  domain registrations and any applications  therefor,  and
          tangible   or   intangible   proprietary   information   or   material
          ("Intellectual  Property")  that are used in the business of Lightseek
          as currently conducted,  except to the extent that the failure to have
          such rights has not had and would not reasonably be expected to have a
          Material Adverse Effect on Lightseek.

     (b)  Lightseek has not been sued in any suit,  action or proceeding and has
          not  brought  any  action,  suit or  proceeding  for  infringement  of
          Intellectual  Property or breach of any license or agreement involving
          Intellectual  Property  against  any third  party.  The conduct of its
          business does not infringe any  trademark,  service  mark,  copyright,
          trade secret or other proprietary right of any third party, where such
          infringement would have a Material Adverse Effect on Lightseek.

3.11 Interested  Party  Transactions.  Neither  VerticalBuyer  nor  Lightseek is
     indebted to any  director,  officer,  employee or agent (except for amounts
     due as  normal  salaries  and  bonuses  and in  reimbursement  of  ordinary
     expenses),  and no such  person  is  indebted  to either  VerticalBuyer  or
     Lightseek except as disclosed in the Financial Statements.

3.12 Insurance. Neither VerticalBuyer nor Lightseek currently has insurance.

3.13 Compliance  With Laws. To its knowledge,  VerticalBuyer  and Lightseek have
     complied  with,  are not in violation of, and have not received any notices
     of violation with respect to, any federal, state, local or foreign statute,
     law or  regulation  with respect to the conduct of their  business,  or the
     ownership  or  operation  of their  respective  business,  except  for such
     violations  or  failures to comply as could not be  reasonably  expected to
     have a Material Adverse Effect.

3.14 Minute  Books.  VerticalBuyer  will make  available  to CSPI a complete and
     accurate  summary of all meetings of directors and  shareholders or actions
     by written consent since the time of  incorporation of  VerticalBuyer,  and
     reflect all  transactions  referred to in such  minutes  accurately  in all
     material respects.

3.15 Complete Copies of Materials. VerticalBuyer has delivered or made available
     true and complete  copies of each  agreement not in the ordinary  course of
     business to which VerticalBuyer or Lightseek is a party.

3.16 Brokers' and Finders'  Fees.  VerticalBuyer  has not incurred,  nor will it
     incur, directly or indirectly, any liability for brokerage or finders' fees
     or agents'  commissions or investment  bankers' fees or any similar charges
     in connection  with this Agreement or any transaction  contemplated  hereby
     except as set forth in Exhibit 3.16.

3.17 Board  Approval.  This Agreement has been adopted by the Board of Directors
     of VerticalBuyer in resolutions which are in full force and effect.



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<PAGE>

3.18 Representations Complete. None of the representations or warranties made by
     VerticalBuyer,   or  documents  furnished  by  VerticalBuyer  or  Lightseek
     pursuant to this  Agreement  or any  written  statement  furnished  to CSPI
     pursuant hereto or in connection with the transactions contemplated hereby,
     when all such  documents are read together in their  entirety,  contains or
     will  contain at the Closing any untrue  statement of a material  fact,  or
     omits or will omit at the Closing to state any material  fact  necessary in
     order to make the statements  contained herein or therein,  in the light of
     the circumstances under which made, not misleading; provided, however, that
     for  purposes of this  representation,  any document  attached  hereto as a
     "Superseding  Document" (even if not actually  physically  attached hereto)
     that  provides  information  inconsistent  with or in addition to any other
     written  statement  furnished to CSPI in  connection  with the  transaction
     contemplated  hereby, shall be deemed to supersede any other prior document
     or written statement furnished to CSPI with respect to such inconsistent or
     additional information.

3.19 Authorization.  All  acts  and  conditions  required  by law on the part of
     VerticalBuyer  to authorize the execution and delivery of this Agreement by
     VerticalBuyer and the transactions  contemplated herein and the performance
     of all obligations of VerticalBuyer  hereunder have been duly performed and
     obtained,  and this  Agreement  constitutes  a valid  and  legally  binding
     obligation of  VerticalBuyer,  enforceable  in  accordance  with its terms,
     subject,  as to the  enforcement  of remedies,  to  applicable  bankruptcy,
     insolvency, moratorium, reorganization or similar laws affecting creditors'
     rights generally, to general equitable principles and to limitations on the
     enforceability of indemnification provisions as applied to certain types of
     claims arising hereafter, if any, under the federal securities laws.

3.20 Compliance With Other Instruments. The execution,  delivery and performance
     of this Agreement and the  consummation  of the  transactions  contemplated
     hereby will not result in any  violation or default of any provision of any
     instrument,   judgment,   order,   writ,   decree  or   contract  to  which
     VerticalBuyer  or Lightseek is a party or by which it is bound,  or require
     any consent under or be in conflict with or constitute, with or without the
     passage of time and giving of notice,  either a violation or default  under
     any such provision.

3.21 Governmental Consents. No consent,  approval, order or authorization of, or
     registration,  qualification,  designation, declaration or filing with, any
     federal,  regional,  state or local  governmental  authority  of the United
     States on the part of  VerticalBuyer or Lightseek is required in connection
     with the consummation of the  transactions  contemplated by this Agreement,
     except for filings,  if any,  required  pursuant to applicable  federal and
     state  securities  laws,  which  filings  will be made within the  required
     statutory period.

3.22 Litigation.  There is no action, suit, proceeding, or investigation pending
     or,  to  its  knowledge,  currently  threatened  against  VerticalBuyer  or
     Lightseek  which  questions the validity of this  Agreement or the right of
     VerticalBuyer   to  enter  into  this   Agreement  or  to  consummate   the
     transactions contemplated hereby.

3.23 Authorized Shares of Common Stock and Warrants.  The Shares and Warrants to
     be  transferred  to CSPI under this Agreement will be free and clear of any
     lien, pledge,  security interest or other encumbrance and, upon delivery of
     the  securities  at the  Closing as  provided  for in this  Agreement,  and
     assuming  CSPI is  acquiring  the  Shares  and  Warrants  in good faith and
     without notice of any adverse claim,  CSPI will acquire good title thereto,
     free and clear of any lien, pledge, security interest or encumbrance (other
     than restrictions on transfer arising under applicable securities laws).

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<PAGE>

3.24 Disclosure.  VerticalBuyer has fully provided CSPI with all the information
     in its  possession  that  CSPI has  requested  in  determining  whether  to
     purchase the securities offered by VerticalBuyer. Neither Article 3 of this
     Agreement nor any document  attached to this Agreement nor any  certificate
     delivered  pursuant  hereto  that,  in any such  case,  has been or will be
     provided by or on behalf of VerticalBuyer  contains any untrue statement of
     a material  fact or omits to state a material  fact  necessary  to make the
     statements   made  herein  or  therein  not  misleading  in  light  of  the
     circumstances under which they were made.

3.25 Capital  Structure.   The  capitalization  of  VerticalBuyer   consists  of
     50,000,000  shares  of  common  stock,  par  value  $.001  each,  of  which
     15,000,000  shares are issued and outstanding as of the date of closing and
     5,000,000 shares of "blank check" preferred stock,  $.001 par value each of
     which  none are  issued.  There  are no  other  outstanding  securities  of
     VerticalBuyer  and no  outstanding  commitments  to issue  any  securities,
     except  WE MUST  FILL  THIS  NUMBER  IN  options  and  warrants  issued  to
     employees,  directors and consultants the terms and conditions of which are
     set forth in Exhibit 3.25.

3.26 Taxes.  VerticalBuyer  and  Lightseek  have  timely  filed all tax  returns
     required  to be filed and has paid all taxes shown  thereon to be due.  The
     Financial Statements (i) fully accrue all actual and contingent liabilities
     for taxes with respect to all periods through December 31, 1999 and neither
     VerticalBuyer  nor its  subsidiary  has or will incur any tax  liability in
     excess of the amount reflected on the Financial  Statements with respect to
     such  periods,  and (ii)  properly  accrue  in  accordance  with  generally
     accepted  accounting  principles  all  liabilities  for taxes payable after
     December 31, 1999 with respect to all  transactions and events occurring on
     or prior to such date.  No material tax liability  since  December 31, 1999
     has been  incurred by  VerticalBuyer  or its  subsidiary  other than in the
     ordinary  course of business  and adequate  provision  has been made in the
     Financial  Statements  for all taxes  since  that date in  accordance  with
     generally accepted accounting principles.

3.27 Employee Matters.  To its best knowledge,  VerticalBuyer and its subsidiary
     are in  compliance in all material  respects with all currently  applicable
     laws and regulations respecting  employment,  discrimination in employment,
     terms and conditions of employment,  wages,  hours and occupational  safety
     and  health and  employment9  practices,  and is not  engaged in any unfair
     labor practice. To its best knowledge,  there are no pending claims against
     VerticalBuyer  under any  workers  compensation  plan or policy or for long
     term disability.  All employee benefit plans, stock option plans (including
     the terms and  conditions of any issued and  outstanding  options) or other
     employee stock  issuance plans or rights and all employment  agreements are
     listed on Exhibit 3.27.

3.28 Delivery of Documents.  VerticalBuyer has delivered or will deliver to CSPI
     at or prior to the Closing all  documents  required to be  delivered  under
     this Agreement.

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                                    ARTICLE 4
                     REPRESENTATIONS AND WARRANTIES OF CSPI

         CSPI represents and warrants to VerticalBuyer as follows:

4.01 Organization,  Standing and Power.  CSPI is a corporation  duly  organized,
     validly existing and in good standing under the laws of Massachusetts. CSPI
     has the corporate  power to own its properties and to carry on its business
     as now  being  conducted  and  as  proposed  to be  conducted  and is  duly
     qualified to do business and is in good  standing in each  jurisdiction  in
     which the  failure to be so  qualified  and in good  standing  would have a
     Material Adverse Effect on CSPI.

4.02 Authority.  CSPI has all requisite  corporate  power and authority to enter
     into this Agreement and to consummate the transactions contemplated hereby.
     The execution and delivery of this  Agreement and the  consummation  of the
     transactions contemplated hereby have been duly authorized by all necessary
     corporate action on the part of CSPI. This Agreement has been duly executed
     and delivered by CSPI and constitutes  the valid and binding  obligation of
     CSPI  enforceable  against CSPI in accordance  with its terms,  except that
     such enforceability may be limited by bankruptcy, insolvency, moratorium or
     other similar laws  affecting or relating to creditors'  rights  generally,
     and is subject to general  principles of equity. The execution and delivery
     of  this  Agreement  by  CSPI  does  not,  and  the   consummation  of  the
     transactions  contemplated hereby will not, conflict with, or result in any
     violation of, or default under (with or without notice or lapse of time, or
     both), or give rise to a right of termination, cancellation or acceleration
     of any material  obligation  or loss of any material  benefit under (i) any
     provision of the articles of organization or bylaws of CSPI as amended,  or
     (ii) any material mortgage,  indenture,  lease, contract or other agreement
     or instrument,  permit,  concession,  franchise,  license, judgment, order,
     decree,  statute, law, ordinance,  rule or regulation applicable to CSPI or
     any  of  its  properties  or  assets.  No  consent,   approval,   order  or
     authorization  of, or registration,  declaration or filing with, any court,
     administrative  agency or  commission  or other  governmental  authority or
     instrumentality  ("Governmental  Entity") is required by or with respect to
     CSPI or  CSPI  in  connection  with  the  execution  and  delivery  of this
     Agreement or the  consummation  of the  transactions  contemplated  hereby,
     except  for  (i)  such   consents,   approvals,   orders,   authorizations,
     registrations, declarations and filings as may be required under applicable
     state securities laws and the securities laws of any foreign country,  (ii)
     such other consents,  authorizations,  filings, approvals and registrations
     which, if not obtained or made, would not have a Material Adverse Effect on
     CSPI and/or and would not prevent,  or materially alter or delay any of the
     transactions  contemplated  by this Agreement and (iii) subject,  as to the
     enforcement of remedies, to applicable bankruptcy,  insolvency, moratorium,
     reorganization or similar laws affecting  creditors'  rights generally,  to
     general  equitable  principles and to limitations on the  enforceability of
     indemnification  provisions as applied to certain  types of claims  arising
     hereafter, if any, under the federal securities laws.

4.03 Litigation.  There is no action, suit, proceeding, or investigation pending
     or, to its  knowledge,  currently  threatened  against  CSPI or CSPI  which
     questions the validity of this Agreement or the right of CSPI to enter into
     this Agreement or to consummate the transactions contemplated hereby.

4.04 Delivery of Documents.  CSPI has delivered or will deliver to VerticalBuyer
     at or prior to the Closing all  documents  required to be  delivered  under
     this Agreement.

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                                    ARTICLE 5
           LEGEND REMOVAL, TRANSFER, CERTAIN SALES, ADDITIONAL SHARES

5.01 Removal of Legend.  The Legend  shall be removed  and  VerticalBuyer  shall
     issue,  or shall cause to be issued,  a certificate  without such legend to
     the holder of any security upon which it is stamped,  and a certificate for
     a security  shall be  originally  issued  without the  Legend,  if, (a) the
     resale of such Security is  registered  under the 1933 act, (b) such holder
     provides  VerticalBuyer with an opinion of counsel, in form,  substance and
     scope  customary  for opinions of counsel in  comparable  transactions  and
     reasonably  satisfactory to  VerticalBuyer  and its counsel (the reasonable
     cost of which  shall be borne by  VerticalBuyer  if  neither  an  effective
     registration  statement  under  the 1933 act or Rule  144 is  available  in
     connection  with such sale) to the effect that a public sale or transfer of
     such security may be made without  registration under the 1933 act pursuant
     to an exemption from such registration requirements.

5.02 Transfer  Agent  Instructions.  VerticalBuyer  shall  instruct its transfer
     agent  to  issue  certificates,  registered  in the  name  of  CSPI  or its
     transferees,  for the Shares in such amounts specified from time to time by
     CSPI or its transferees to exercise of the Warrants.

                                    ARTICLE 6
                              ELECTION OF DIRECTOR

6.01 VerticalBuyer  has  taken  all  corporate  and other  action  necessary  to
     establish the size of its Board of Directors and to elect,  effective  upon
     the Closing, Alexander Lupinetti to be one of the four directors.  Vertical
     Buyer  agrees not to change the number of directors  constituting  the full
     Board of Directors  except in accordance  with the Voting  Agreement by and
     between the Parties of even date herewith.

                                    ARTICLE 7
                    CONDITIONS TO OBLIGATIONS OF THE PARTIES

     The  obligations of CSPI on the one hand, and  VerticalBuyer,  on the other
hand, to the following conditions on or prior to the Closing:

7.01 Consents and  Approvals.  The Parties  shall have obtained all consents and
     approvals of third parties and governmental  authorities,  if any, required
     to consummate the transactions contemplated by this Agreement.

7.02 Representations,   Warranties  and  Agreements.   All  representations  and
     warranties made herein by CSPI and VerticalBuyer,  shall be true,  accurate
     and correct in all respects as of the date made and as of the Closing. CSPI
     and  VerticalBuyer,  shall have  performed all  obligations  and agreements
     undertaken  by each of them  herein  to be  performed  at or  prior  to the
     Closing.

7.03 Certificate.  CSPI shall have received from VerticalBuyer and VerticalBuyer
     shall have received from CSPI, a  certificate,  dated as of the Closing and
     executed  by the  President  or Chief  Executive  Office and  Secretary  of
     VerticalBuyer and CSPI,  respectively to the effect that the conditions set
     forth in Article 3 or Article 4 respectively shall have been satisfied.

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<PAGE>

7.04 No Material  Adverse  Changes.  There shall not have  occurred any material
     adverse change in the financial  condition,  properties,  assets (including
     intangible  assets),  liabilities,   business,  operations  or  results  of
     operations of VerticalBuyer or Lightseek.

7.05 No Actions. Consummation of the transactions contemplated by this Agreement
     shall  not  violate  any  order,   decree  or  judgment  of  any  court  or
     governmental body having jurisdiction.

7.06 Proceedings  and  Documents.   All  corporate  and  other   proceedings  in
     connection with the transactions  contemplated hereby and all documents and
     instruments  incident to such  transactions  shall be in form and substance
     reasonably  satisfactory to counsel for each of the Parties,  and each such
     Party (or its counsel) shall have received all such  counterpart  originals
     or  certified  or  other  copies  of such  documents  as it may  reasonably
     request.

7.07 Accuracy  of  Documents  and  Information.   The  copies  of  all  material
     instruments,  agreements, other documents and written information delivered
     to any Party by any other  Party or its  representatives  shall be complete
     and correct in all material respects as of the Closing.

7.08 Execution of  Agreements.  The Parties will have executed the  Registration
     Rights  Agreement  and  Voting  Agreement  in the form  attached  hereto as
     Exhibit 2.02.

                                    ARTICLE 8
                                 INDEMNIFICATION

8.01 Indemnification.  Each Party will  indemnify  and hold  harmless  the other
     Party and its respective  officers,  directors,  agents and employees,  and
     each person, if any, who controls or may control a Party within the meaning
     of the 1933  act  from and  against  any and all  losses,  costs,  damages,
     liabilities and expenses arising from claims,  demands,  actions, causes of
     action,  including,  without limitation,  reasonable legal fees, except for
     the net of any recoveries under existing insurance  policies,  tax benefits
     received  by any  Party  or its  affiliates  as a result  of such  damages,
     indemnities from third parties or in the case of third party claims, by any
     amount  actually  recovered  by a  Party  or  its  affiliates  pursuant  to
     counterclaims  made by any of them  directly  relating to the facts  giving
     rise to such third party claims  (collectively,  "Damages")  arising out of
     any misrepresentation or breach of or default in connection with any of the
     representations,  warranties,  covenants  and  agreements  given or made by
     VerticalBuyer or CSPI in this Agreement, or any exhibit or schedule to this
     Agreement.  Each Party and its affiliates  shall act in good faith and in a
     commercially  reasonable  manner to mitigate  any damages  they may suffer.

                                    ARTICLE 9
                                 MISCELLANEOUS

9.01 Notices. Any notice given hereunder shall be in writing and shall be deemed
     effective  upon  the  earlier  of  personal  delivery  (including  personal
     delivery  by  facsimile)  or the third day after  mailing by  certified  or
     registered mail, postage prepaid, as follows:

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<PAGE>

         (a)      If to CSPI:
                  Alexander Lupinetti
                  Chief Executive Officer
                  40 Linnell Circle
                  Billerica, MA 01821

                  with a copy to Dean F. Hanley, Esquire
                  Foley, Hoag & Eliot LLP
                  One Post Office Square
                  Boston, Massachusetts 02109
                  Phone: 617-832-1000
                  Facsimile: 617-832-7000

         (b)      If to VerticalBuyer:
                  Tim Rosen
                  President
                  c/o Donahue & Associates
                  83 Meadow Road West.
                  Trumbull, Connecticut 06611

     or to such other address as any Party may have  furnished in writing to the
     other Party in the manner provided above.

9.02 Entire Agreement;  Modifications;  Waiver. This Agreement and the documents
     and  instruments  and  other  agreements  specifically  referred  to herein
     constitute the final,  exclusive and complete  understanding of the Parties
     with respect to the subject  matter hereof and supersedes any and all prior
     agreements,   understandings  and  discussions  with  respect  thereto.  No
     variation or  modification of this Agreement and no waiver of any provision
     or condition hereof, or granting of any consent  contemplated hereby, shall
     be valid unless in writing and signed by the Party against whom enforcement
     of any such  variation,  modification,  waiver or consent  is  sought.  The
     rights and remedies  available to each Party pursuant to this Agreement and
     all exhibits hereunder shall be cumulative.

9.03 Captions. The captions in this Agreement are for convenience only and shall
     not be considered a part of or affect the construction or interpretation of
     any provision of this Agreement.

9.04 Counterparts. This Agreement may be executed in any number of counterparts,
     each of which when so executed  shall  constitute  an original copy hereof,
     but all of which together shall constitute one agreement.

9.05 Publicity.  Except for disclosure required by any law to which either Party
     is subject, the timing and content of any announcements, press releases and
     public  statements  to  be  made  prior  to  the  Closing   concerning  the
     transactions  contemplated  hereby  shall be  determined  solely by CSPI in
     consultation with VerticalBuyer.

9.06 Successors  and Assigns.  No Party may,  without the prior express  written
     consent of each other  Party,  assign this  Agreement  in whole or in part.
     This  Agreement  shall be  binding  upon and  inure to the  benefit  of the
     respective successors and permitted assigns of the Parties.

9.07 Governing  Law.  This  Agreement  shall be  governed by and  construed  and
     enforced in accordance  with the  substantive  laws of The  Commonwealth of
     Massachusetts without regard to its principles of conflicts of laws.

                                       13
<PAGE>

9.08 Further  Assurances.  At the  request of any of the  Parties,  and  without
     further  consideration,  the other Parties agree to execute such  documents
     and  instruments  and to do  such  further  acts  as may  be  necessary  or
     desirable to effectuate the transactions  contemplated hereby,  required by
     law, statute, rule or regulation.

9.09 Confidentiality and Nondisclosure  Agreements.  All information which shall
     have been furnished or disclosed by one Party to the other pursuant to this
     Agreement,  including without limitation,  business, financial and customer
     development plans, forecasts,  strategies and information, shall be held in
     confidence  pursuant  hereto and shall not be disclosed to any person other
     than their respective employees,  directors, legal counsel,  accountants or
     financial  advisors,  with a need to have access to such  information,  and
     shall not make any use  whatsoever of such  information  except to evaluate
     such  information  internally.  The  confidentiality  provisions  set forth
     herein shall survive until two years from the date hereof, unless the Party
     desiring to disclose the information can document that (i) such information
     is (through no improper  action or inaction by such Party or any affiliate,
     agent,  consultant or employee)  generally available to the public, or (ii)
     was in its possession or known by it prior to receipt from the other Party,
     or (iii)  was  rightfully  disclosed  to it by a third  party,  or (iv) was
     independently  developed  by employees of such Party who have had no access
     to such information.

9.10 Severability.  The  invalidity  or  unenforceability  of any  one  or  more
     phrases,  sentences,  clauses or  provisions  of this  Agreement  shall not
     affect the validity or  enforceability  of the  remaining  portions of this
     Agreement or any part thereof.

     IN WITNESS  WHEREOF,  each Party has executed this Agreement as of the date
first above written.

                                       CSP INC.

                                       By: /s/ Alexander R. Lupinetti
                                           ----------------------------
                                            Alexander R. Lupinetti,
                                               Chief Executive Officer

                                       VERTICALBUYER, INC.

                                        By: /s/ Tim Rosen
                                            ----------------------
                                            Tim Rosen,
                                               President




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