Since it takes two to negotiate and a third party to agree it is at times frustrating to find that one is out of sink or reason. We realtors do our best. Sometimes our best is not good enough. You Can Lead a Horse to Water but You Can't Make Him Drink
Yes there are a lot of short sale "scammers" out there offering "negotiators" etc and claiming the Seller and Age ants will not have to pay the exorbitant fees of thousands of dollars. The problem is the "buyer" will have to pay it and this will make it more difficult to get the transaction done so we can get paid our commissions.
So I would recommend that you not get involved with "negotiating" with the bank. Just submit whatever the seller gives you or better yet have the seller do their own "negotiation" as far as promisory notes, etc.