What a dick, from now on if someone looks at it and "commits" you take a non-refundable down payment. If they don't want to, then you don't wait. It goes to the first person to bring cash. Money talks.
A guy I know took $1500 as a down payment on a car he was selling and the buyer backed out last minute. $1500 richer.
Hope you can get it to move soon, especially if you are ready to move on. Just wasn't the right buyer thats all.