What patents would be a problem then? I think there is real legroom for a product that ignores the eBay sweetharts (super-resellers) and focusses more on the individual occasional sellers that use common sense and trust to make a transaction.
I recently had some issues with eBay where I had to relist an item 3 times because of scammers. Why does your item disappear before the deal is DONE? Why not have ME decide when it is sold, and not the buyer?