I also had a similar scenario as cam's. The sales agreement for selling our last boat, was recorded at a lesser amount than the actual selling price, due to a three-way negotiation.
Since I would not bend or compromise on my listed price, and the buyer claimed his offer was as much as he could budget, my broker split the difference with the buyer in a cash settlement - thereby reducing his commission. The higher selling price may have not been possible, if this was a co-broke situation.
True Blue . . .
sold the Nauticat