Encore Investments, Inc.
                                       And
                              Sigma Solutions, Inc.

                                  March 2, 2000

                      Amendment to Stock Purchase Agreement

Omar A. Rizvi, President
Origin Investment Group, Inc.
One Magnificent Mile
980 North Michigan Avenue, Suite 1400
Chicago, IL 60611


Re:  Stock  Purchase   Agreement   dated  effective  as  of  December  31,  1999
     ("Agreement"),  by and among Origin Investment Group, Inc.  ("Buyer"),  and
     Gene V. Larsen,  Bertrand O. Baetz,  Jr.,  Frank G.  Jarzombek and Scott E.
     Gruendler ("Sellers").


Dear Omar:

     By this letter, Buyer and Sellers amend the Agreement as follows, effective
the date hereof:

     1.  Extension of Closing Date.  Subject to Buyer  satisfying the conditions
listed in paragraph 2 below on or before  March 8, 2000,  we agree to extend the
Closing  Date from March 8, 2000,  to March 22,  2000.  Please  understand  that
Sellers do not intend to extend the Closing Date beyond March 22, 2000. The date
in paragraph 9(d) will also be extended from March 8, 2000, to March 22, 2000.

     2.  Conditions  to Extension of Closing  Date.  Buyer must satisfy 2(a) and
2(b), fully and unconditionally, on or before March 8, 2000, and 2(c), fully and
unconditionally,  on or before March 31, 2000,  in order to obtain the extension
of the Closing Date set forth in Paragraph 1:
                                      -1-
<PAGE>
     (a) Buyer  shall  deliver the form of, and the  written  confirmation  of a
major national bank,  acceptable to Sellers in their sole  discretion,  that the
bank  will  issue in favor of  Sellers  an  irrevocable  letter of credit in the
amount of $1.3 million upon which Sellers may draw on the first  anniversary  of
the Closing Date.

     (b) Buyer shall deliver to Sellers a cashier's check issued by a nationally
recognized  bank in the  amount of  $100,000  payable  to  Sellers,  to fund the
payment of the "break up" fee described herein.

     (c) BDO Seidman Audit. Buyer shall cause BDO Seidman,  L.L.P. to deliver to
Sellers no less than 3 original  copies of its signed  final audit report on the
financial  statements of the Acquired Company.  If BDO Seidman has not completed
its signed  final  audit by March 31,  2000,  Buyer  shall  cause BDO Seidman to
finish their audit report,  at Buyer's sole cost, and deliver the 3 signed final
audit reports to Sellers as soon as possible.

     3. "Break Up" Fee.  Sellers may deposit the  $100,000  "break up" fee to be
paid pursuant to Paragraph  2(c) in their  personal  accounts.  Sellers shall be
entitled  to all  interest  and  earnings  on the  deposit and shall be under no
obligation  to repay or refund the payment or any interest or earnings  thereon.
If the Closing occurs prior to March 23, 2000,  Buyer shall be given a credit of
$100,000 against the cash payment payable to Sellers,  as adjusted below. If the
Closing does not occur before March 23, 2000,  the  Agreement  shall  terminate,
subject to all rights of either party for any breaches  occurring prior thereto,
and Seller shall retain the payment.

     4. Purchase Price Increase.  The cash payment payable to Sellers at Closing
by Buyer pursuant to Paragraph  2.2(a) and Paragraph  2.4(b)(i) of the Agreement
is increased  to $2.75  million if the Closing  occurs after March 8, 2000.  All
other amounts and  consideration  payable to Sellers  under the Agreement  shall
remain the same, and shall not be decreased by the additional cash to be paid at
Closing.

     5. Broker.  The Heim Group, Inc. ("Heim Group") expressly  acknowledges and
agrees that if the Closing does not occur on or before March 22, 2000,  the Heim
Group will only be entitled  to $12,500 out of any funds paid to Sellers,  being
one-half of the  original  "break up" fee. The Heim Group  expressly  waives any
rights they may have to the increased "break up" fee.

                                     * * * *

     Except as specifically  amended by this letter,  the terms of the Agreement
shall continue.  All capitalized  terms used herein shall have the meaning given
to them in the Agreement.
                                      -2-
<PAGE>
     Please sign a copy of this letter where indicated  below,  and return it to
us on or before 5:00 p.m. San Antonio  time,  March 6, 2000,  whereupon it shall
become our binding agreement.


     Very Truly Yours,

                                                /S/ GENE V. LARSEN
                                                -----------------------------
                                                Gene V. Larsen

                                                /S/ BERTRAND O. BAETZ, JR.
                                                -----------------------------
                                                Bertrand O. Baetz, Jr.


                                                /S/ FRANK G. JARZOMBEK
                                                -----------------------------
                                                Frank G. Jarzombek

                                                /S/ SCOTT E. GRUENDLER
                                                -----------------------------
                                                Scott E. Gruendler


AGREED:

Origin Investment Group, Inc.


By:  /S/ OMAR A. RIZVI
     -------------------------
     Omar A. Rizvi, President

     Date: March 6, 2000


The Heim Group, Inc.

By:  /S/ GORDON GREVE
     -------------------------

Date: March 6, 2000

cc:      Mike Kreager
         Law Offices of Mike Kreager, P.C.
         7744 Broadway, Suite 204
         San Antonio, Texas 78209-3262