Put everything in writing. Agreed price time, to complete the sale after a reasonable CASH down payment. If no cash down at agreement time it has not been sold, keep showing it. The first one with CASH down gets a very little time to complete, no wife is out of town unless he wants to buy those days with CASH say $100. per day. He looses it if it never gets sold. Or if you feel like being a nice guy and sell it fast enough return half.