Take a look at a little system in which I'm testing at the moment. It's like eBay but will be much more secure when I write my own code for it
Could be a success, still in BETA stage, but this will change.
Could be used for hardware like they do here @ oc3d on the forum, allows image uploads, info description, price, auto email of reply, questions box etc...
Highest bidder get's item :P. You should be able to set the one click buy button soon.