Yes possibly something to consider. However, the only problem is, is that the person buying may claim to be unhappy with the find, and doesnt want to pay etc. Could cause alot of problems.
However, I have been considering something along those lines which would link with this. After a suggestion yesterday, something which is being considered is a optional subscription service, where subscribers would get benefits over reular users. Still under consideration though, alot to sort out.
James