<PAGE>   1
                                                                  EXHIBIT 10.4
                                                                  ------------

                                   AGREEMENT

                 AGREEMENT (this "AGREEMENT"), dated as of July 7, 2000, by
and between Waxman USA Inc., a Delaware corporation (the "STOCKHOLDER") and
Barnett Inc., a Delaware corporation (the "COMPANY").

                             W I T N E S S E T H:
                             --------------------

                 WHEREAS, concurrently herewith, Wilmar Industries, Inc., a
New Jersey corporation ("PARENT") and BW Acquisition, Inc., a Delaware
corporation and a wholly-owned subsidiary of Parent, ("MERGER SUB" and,
together with Parent, "PURCHASER") and the Company are entering into an
Agreement and Plan of Merger of even date herewith (the "MERGER AGREEMENT"),
pursuant to which Purchaser will acquire all of the outstanding shares of
common stock, $0.01 par value per share, of Company (the "COMMON STOCK"), for
the Merger Consideration, as defined in the Merger Agreement in effect on the
date hereof, pursuant to a merger of Merger Sub with and into Company (the
"MERGER");

                 WHEREAS, the Stockholder is a holder of record and
beneficially owns, as of the date hereof, 7,186,530 shares of Common Stock
(the "EXISTING SHARES", together with any shares of Common Stock acquired
after the date hereof and prior to the termination hereof, hereinafter
collectively referred to as the "SHARES"), of which 1,000,000 Existing Shares
are pledged (the "PLEDGED SHARES") to Congress Financial Corporation
("CONGRESS") as collateral security for the Stockholder's obligations to
Congress pursuant to that certain Loan and Security Agreement, dated as of
June 17, 1999 and amended as of December 8, 1999, March 29, 2000, May 1, 2000
and July __, 2000, by and among Congress, Waxman Consumer Products Group,
Inc., WOC Inc., Western American Manufacturing Inc., WAMI Sales, Inc.,
Stockholder, Waxman Industries, Inc. ("Waxman") and TWI, International, Inc.
(the "CONGRESS CREDIT FACILITY");

         WHEREAS, concurrently herewith, the Stockholder and Waxman are
entering into a Stockholder Agreement (the "Stockholder Agreement") and Voting
Trust Agreement (the "Voting Trust Agreement") with Parent and Merger Sub,
which provide for, among other things, the Stockholder to deposit 6,186,530
shares of the Common Stock beneficially owned by the Stockholder in a voting
trust, and the agreement of the Stockholder and the voting trustee named
therein to vote all shares of Common Stock beneficially owned by the
Stockholder in favor of approval and adoption of the Merger Agreement and the
transactions contemplated thereby, and the Stockholder delivered to Parent and
Merger Sub an irrevocable proxy (the "Irrevocable Proxy") in respect of an
additional 1,000,000 of such shares of Common Stock beneficially owned by the
Stockholder;

                  WHEREAS, this Agreement is being entered into concurrently
with the execution of the Merger Agreement.




                                       1

<PAGE>   2




                  NOW, THEREFORE, in consideration of the premises and the
mutual covenants and agreements herein contained and for such other good and
valuable consideration, the receipt and sufficiency of which is hereby
acknowledged, and intending to be legally bound hereby, the parties hereto
agree as follows:

1. DEFINITIONS. Capitalized terms used and not defined herein have the
respective meanings ascribed to them in the Merger Agreement.

2. STANDBY PURCHASE COMMITMENT. Provided that the Merger Agreement has not
been terminated in accordance with its terms, if the Effective Time has not
occurred by September 1, 2000, then, subject to the terms and conditions set
forth herein, the Company shall purchase from the Stockholder, and the
Stockholder shall sell to the Company, on September 1, 2000 (the "Closing
Date"), free and clear of all liens and encumbrances (other than restrictions
imposed by federal and state securities laws), that number of shares of Common
Stock (rounded up to the nearest whole number of shares) (the "Purchase
Shares") determined by dividing $2,000,000 (the "Purchase Price") by the
average closing price, as reported on the Nasdaq National Market, for shares
of Common Stock for the ten (10) trading days preceding September 1, 2000.

3. PAYMENT OF PURCHASE PRICE. The Company shall pay for the Purchase Shares by
wire transfer of the Purchase Price in immediately available funds to the
following account or other account designated in writing by Stockholder not
less than two business days prior to September 1, 2000: Firstar N.A.
Milwaukee, WI, ABA # 042000013, Acct. Name Waxman USA Inc., Acct. # 821689312.

4. DELIVERY OF CERTIFICATE TO VOTING TRUSTEE. To effect the Closing, on the
Closing Date, the Company shall, pursuant to Section 6 of the Voting Trust
Agreement, send written notice to the Voting Trustee certifying that it has
paid the Purchase Price pursuant to Section 3 hereof. The Stockholder shall
cause certificates representing the Purchase Shares to be delivered to the
Company, in accordance with the Voting Trust Agreement, free and clear of all
liens and encumbrances (other than restrictions imposed by federal and state
securities laws).

5.  MISCELLANEOUS.

         a. SUCCESSORS AND ASSIGNS. The provisions of this Agreement shall be
         binding upon and inure to the benefit of the parties hereto and their
         respective successors and assigns, provided that no party may assign,
         delegate or otherwise transfer any of its rights or obligations under
         this Agreement without the consent of the other parties hereto.

         b.  GOVERNING LAW AND VENUE; WAIVER OF JURY TRIAL.

                  i.       THIS AGREEMENT SHALL BE DEEMED TO BE MADE IN AND IN
                           ALL RESPECTS SHALL BE INTERPRETED, CONSTRUED AND




                                       2

<PAGE>   3



                           GOVERNED BY AND IN ACCORDANCE WITH THE LAW OF THE
                           STATE OF DELAWARE. The parties irrevocably submit
                           to the jurisdiction of the federal courts of the
                           United States of America located in the State of
                           Delaware solely in respect of the interpretation
                           and enforcement of the provisions of this Agreement
                           and of the documents referred to in this Agreement,
                           and in respect of the transactions contemplated by
                           this Agreement and by those documents, and hereby
                           waive, and agree not to assert, as a defense in any
                           action, suit or proceeding for the interpretation
                           or enforcement of this Agreement or of any such
                           document, that it is not subject to this Agreement
                           or that such action, suit or proceeding may not be
                           brought or is not maintainable in said courts or
                           that the venue thereof may not be appropriate or
                           that this Agreement or any such document may not be
                           enforced in or by such courts, and the parties
                           hereto irrevocably agree that all claims with
                           respect to such action or proceeding shall be heard
                           and determined in such a federal court. The parties
                           hereby consent to and grant any such court
                           jurisdiction over the person of such parties and
                           over the subject matter of such dispute and agree
                           that mailing of process or other papers in
                           connection with any such action or proceeding in
                           the manner provided herein or in such other manner
                           as may be permitted by law, shall be valid and
                           sufficient service thereof.

                  ii.      EACH PARTY ACKNOWLEDGES AND AGREES THAT ANY
                           CONTROVERSY WHICH MAY ARISE UNDER THIS AGREEMENT IS
                           LIKELY TO INVOLVE COMPLICATED AND DIFFICULT ISSUES,
                           AND THEREFORE EACH SUCH PARTY HEREBY IRREVOCABLY
                           AND UNCONDITIONALLY WAIVES ANY RIGHT SUCH PARTY MAY
                           HAVE TO A TRIAL BY JURY IN RESPECT OF ANY LITIGATION
                           DIRECTLY OR INDIRECTLY ARISING OUT OF OR RELATING TO
                           THIS AGREEMENT, OR THE TRANSACTIONS CONTEMPLATED BY
                           THIS AGREEMENT.  EACH PARTY CERTIFIES AND
                           ACKNOWLEDGES THAT (i) NO REPRESENTATIVE, AGENT OR
                           ATTORNEY OF ANY OTHER PARTY HAS REPRESENTED,
                           EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY WOULD
                           NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE THE
                           FOREGOING WAIVER, (ii) EACH SUCH PARTY UNDERSTANDS
                           AND HAS CONSIDERED THE IMPLICATIONS OF THIS WAIVER,
                           (iii) EACH SUCH PARTY MAKES THIS WAIVER VOLUNTARILY,
                           AND (iv) EACH SUCH PARTY HAS BEEN INDUCED TO ENTER
                           INTO THIS AGREEMENT BY, AMONG OTHER THINGS, THE
                           MUTUAL WAIVERS AND CERTIFICATIONS IN THIS SECTION.

         c. COUNTERPARTS; EFFECTIVENESS. This Agreement may be signed in any
         number of counterparts, each of which shall be an original, with the
         same effect as if the signatures thereto and hereto were upon the
         same instrument. This Agreement shall become effective




                                       3

<PAGE>   4



         when each party hereto shall have received counterparts hereof signed
         by all of the other parties hereto.

         d. SEVERABILITY. If any term or other provision of this Agreement is
         invalid, illegal or incapable of being enforced by any law, or public
         policy, all other conditions and provisions of this Agreement shall
         nevertheless remain in full force and effect so long as the economic
         or legal substance of the transactions contemplated hereby is not
         affected in any manner materially adverse to any party. Upon such
         determination that any term or other provision is invalid, illegal or
         incapable of being enforced, the parties hereto shall negotiate in
         good faith to modify this Agreement so as to effect the original
         intent of the parties as closely as possible in an acceptable manner
         to the end that transactions contemplated hereby are fulfilled to the
         extent possible.

         e. ENTIRE AGREEMENT; NO THIRD PARTY BENEFICIARIES. This Agreement
         constitutes the entire agreement, and supersedes all prior
         agreements, representations and warranties, and understandings, both
         written and oral, among the parties with respect to the subject
         matter of this Agreement and is not intended to confer upon any
         person other than the parties any rights or remedies.





                                       4

<PAGE>   5


                  IN WITNESS WHEREOF, each of the parties hereto has caused
this Agreement to be executed on its behalf by its officers thereunder to duly
authorized, all as of the date first above written.

                                           WAXMAN USA INC.

                                           By:  /s/  Armond Waxman
                                              ----------------------------------
                                            Name:   Armond Waxman
                                            Title:  President and Co-CEO



                                           BARNETT INC.

                                           By:  /s/  William Pray
                                              ----------------------------------
                                            Name:   William Pray
                                            Title:  Chief Executive Officer








                                       5