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                           OFFER TO PURCHASE FOR CASH

                     ALL OUTSTANDING SHARES OF COMMON STOCK
           (INCLUDING THE ASSOCIATED RIGHTS TO PURCHASE COMMON STOCK)
                                       OF

                                  COMPUSA INC.
                                       AT

                              $10.10 NET PER SHARE
                                       BY

                             TPC ACQUISITION CORP.
                          A WHOLLY OWNED SUBSIDIARY OF

                          GRUPO SANBORNS, S.A. DE C.V.

  THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00 MIDNIGHT, NEW YORK CITY
       TIME, ON TUESDAY, FEBRUARY 29, 2000, UNLESS THE OFFER IS EXTENDED.

                                                                February 1, 2000

To Brokers, Dealers, Commercial Banks,
Trust Companies and Other Nominees:

     We have been engaged by TPC Acquisition Corp., a Delaware corporation
("Purchaser") and a wholly owned subsidiary of Grupo Sanborns, S.A. de C.V., a
corporation organized under the laws of the United Mexican States ("Parent"), to
act as Information Agent in connection with its offer to purchase all of the
outstanding shares of common stock, par value $.01 per share, of CompUSA Inc., a
Delaware corporation (the "Company"), including the associated common stock
purchase rights issued pursuant to the Rights Agreement, dated as of April 29,
1994, as amended as of January 23, 2000, between the Company and American Stock
Transfer & Trust Company (formerly Bank One, Texas, N.A.), as Rights Agent (the
"Shares"), at $10.10 per Share, net to the seller in cash, upon the terms and
subject to the conditions set forth in the Offer to Purchase, dated February 1,
2000 (the "Offer to Purchase") of Purchaser and in the related Letter of
Transmittal (which, as amended or supplemented from time to time, together
constitute the "Offer"). Please furnish copies of the enclosed materials to
those of your clients for whom you hold Shares registered in your name or in the
name of your nominee.

     THE OFFER IS CONDITIONED UPON, AMONG OTHER THINGS, THERE BEING VALIDLY
TENDERED AND NOT WITHDRAWN PRIOR TO THE EXPIRATION OF THE OFFER, THAT NUMBER OF
SHARES WHICH, TOGETHER WITH ANY SHARES THEN BENEFICIALLY OWNED BY PARENT OR
PURCHASER OR ANY OF THEIR RESPECTIVE AFFILIATES, REPRESENTS AT LEAST TWO-THIRDS
OF THE ISSUED AND OUTSTANDING SHARES ON A FULLY DILUTED BASIS.

     Enclosed herewith are the following documents:

          1.  Offer to Purchase, dated February 1, 2000;

          2.  Letter of Transmittal to be used by shareholders of the Company in
     accepting the Offer;

          3.  Notice of Guaranteed Delivery;

          4.  Guidelines for Certification of Taxpayer Identification Number on
     Substitute Form W-9;
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          5.  Letter to shareholders of the Company from the President and Chief
     Executive Officer of the Company, accompanied by the Company's
     Solicitation/Recommendation Statement on Schedule 14D-9;

          6.  A printed form of a letter that may be sent to your clients for
     whose account you hold Shares in your name or in the name of your nominee,
     with space provided for obtaining such clients' instructions with regard to
     the Offer; and

          7.  Return envelope addressed to Citibank, N.A., the Depositary.

     The Offer is being made pursuant to a Merger Agreement (the "Merger
Agreement"), dated as of January 23, 2000, by and among the Company, Parent and
Purchaser, pursuant to which, after completion of the Offer and the satisfaction
or waiver of certain conditions, Purchaser will be merged with and into the
Company and the Company will be the surviving corporation (the "Merger") and
each issued and outstanding Share (other than Shares owned by Parent, Purchaser
or any subsidiary or affiliate of Parent, Purchaser or the Company or held in
the treasury of the Company or held by shareholders who properly exercise
dissenters' rights, if any) will, by virtue of the Merger and without any action
on the part of the holder thereof, be converted into and represent the right to
receive the price per Share paid by Purchaser pursuant to the Offer, without
interest.

     THE BOARD OF DIRECTORS OF THE COMPANY HAS UNANIMOUSLY APPROVED THE MERGER
AGREEMENT, THE OFFER AND THE MERGER, DETERMINED THAT THE OFFER AND THE MERGER
ARE ADVISABLE AND FAIR TO, AND IN THE BEST INTERESTS OF, THE HOLDERS OF SHARES
(OTHER THAN PARENT AND ITS AFFILIATES) AND UNANIMOUSLY RECOMMENDS THAT
SHAREHOLDERS ACCEPT THE OFFER AND TENDER THEIR SHARES PURSUANT TO THE OFFER.

     Upon the terms and subject to the conditions of the Offer (including, if
the Offer is extended or amended, the terms and conditions of any such extension
or amendment), Purchaser will be deemed to have accepted for payment, and will
pay for, all Shares validly tendered and not properly withdrawn by the
Expiration Date (as defined in the Offer to Purchase) as, if and when Purchaser
gives oral or written notice to the Depositary of the Purchaser's acceptance of
the tenders of such Shares for payment pursuant to the Offer. Payment for Shares
accepted for payment pursuant to the Offer will be made only after timely
receipt by the Depositary of (a) certificates for (or a Book-Entry Confirmation
(as defined in the Offer to Purchase) with respect to) such Shares, (b) a
properly completed and duly executed Letter of Transmittal (or facsimile
thereof) or, in the case of a book-entry transfer, an Agent's Message (as
defined in the Offer to Purchase) in lieu of the Letter of Transmittal and (c)
any other documents required by the Letter of Transmittal. Accordingly,
tendering shareholders may be paid at different times depending upon when
certificates for Shares or Book-Entry Confirmations with respect to Shares are
actually received by the Depositary. UNDER NO CIRCUMSTANCES WILL INTEREST BE
PAID ON THE PURCHASE PRICE FOR SHARES, REGARDLESS OF ANY EXTENSION OF THE OFFER
OR ANY DELAY IN MAKING PAYMENT PURSUANT TO THE OFFER.

     The Offer is not being made to (nor will tenders be accepted from or on
behalf of) holders of Shares in any jurisdiction in which the making or
acceptance of the Offer would not be in compliance with the laws of such
jurisdiction. In any jurisdiction where the securities, blue sky or other laws
require the Offer to be made by a licensed broker or dealer, the Offer will be
deemed to be made on behalf of Purchaser by one or more registered brokers or
dealers that are licensed under the laws of such jurisdiction. An envelope in
which to return your instructions to us is enclosed. If you authorize tender of
your Shares, all such Shares will be tendered unless otherwise indicated in such
instruction form. Please forward your instructions to us as soon as possible to
allow us ample time to tender Shares on your behalf prior to the expiration of
the Offer.

     In order to tender Shares pursuant to the Offer, a properly completed and
duly executed Letter of Transmittal (or facsimile thereof), with any required
signature guarantees, or an Agent's Message (in the case of any book-entry
transfer), and any other documents required by the Letter of Transmittal, should
be sent to the Depositary, and either certificates representing the tendered
Shares should be delivered or such Shares must be delivered to the Depositary
pursuant to the procedures for book-entry transfers, all in accordance with the
instructions set forth in the Letter of Transmittal and the Offer to Purchase.

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     Neither Parent nor Purchaser will pay any fees or commissions to any broker
or dealer or other person (other than the Information Agent and the Depositary
as described in the Offer to Purchase) in connection with the solicitation of
tenders of Shares pursuant to the Offer. You will be reimbursed upon request for
customary mailing and handling expenses incurred by you in forwarding the
enclosed offering materials to your clients.

     YOUR PROMPT ACTION IS REQUESTED. WE URGE YOU TO CONTACT YOUR CLIENTS AS
PROMPTLY AS POSSIBLE. THE OFFER AND WITHDRAWAL RIGHTS WILL EXPIRE AT 12:00
MIDNIGHT, NEW YORK CITY TIME, ON TUESDAY, FEBRUARY 29, 2000, UNLESS THE OFFER IS
EXTENDED.

     Any inquiries you may have with respect to the Offer may be addressed to
the undersigned at the address and telephone numbers set forth on the back cover
page of the Offer to Purchase. Additional copies of enclosed materials may be
obtained from the Information Agent and will be furnished at Purchaser's
expense.

                                          Very truly yours,

                                          [MACKENZIE PARTNERS, INC.]

     NOTHING CONTAINED HEREIN OR IN THE ENCLOSED DOCUMENTS SHALL RENDER YOU OR
ANY PERSON THE AGENT OF PURCHASER, PARENT, THE COMPANY, ANY AFFILIATE OF THE
COMPANY, THE INFORMATION AGENT OR THE DEPOSITARY, OR AUTHORIZE YOU OR ANY OTHER
PERSON TO USE ANY DOCUMENT OR MAKE ANY REPRESENTATION ON BEHALF OF ANY OF THEM
WITH RESPECT TO THE OFFER NOT CONTAINED IN THE OFFER TO PURCHASE OR THE LETTER
OF TRANSMITTAL.

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