Get back in touch with him and see what his "best Price" is - skint or not. If it acceptable to you then you can accept and hold onto your goods until he mas the money to pay you, if not, then let the auction run its course.
I would suggest that the latter is the best option anyway, lots of buyers (myself included) wait until the last few hours to browse the items for sale and put in a last minute offer. In this way it is often the last 20 minutes that the price really goes up.
I would not be concerned at fraud or anything else, you obviousely wont be sending the goods to him until he has paid, will you???