Sounds like a cool idea… I also think it would also be fun/a challenge to add a bidding ebay aspect to it for ones put up for sale, leaving the item up until a certain date and time while people bid.

This way people can get more flezz for things they sell, and you have a chance to buy things if you didn’t see it up for sale right when it went up.

edit – I guess this would make my idea pro-scammer but whatever **** can’t be too easy it’s boring… getting moar files should be a bit of a challenge and not just like items in stores.