Dallas, there are no costs associated with filing Rule 144 paperwork through BofA -- none whatsoever -- and no margin requirements or equity requirements on your investment account with them either. My BofA account had $0 in it when I sent them my cert. As a matter of fact, notice on the 144 form itself (standard SEC form) where the filer is required to state that he/she has NOT paid any fees to file the form beyond brokerage fees, so the total fee is entirely dependant on what the broker decides to charge to provide the service to customers.
BofA does, however, charge $42.50 to process an order to sell formerly restricted shares once the 144 forms have been submitted and processed.
I should also say that I did spend about $17 when I overnighted my cert to BofA, and then another $17 when I signed and overnighted the paperwork that BofA faxed to me back out to their office in NYC.