Hi there, it's my first post here - proud to be part of such a great forum!
I have used ebid in the past and find this to be the most reasonable but sadly nothing can beat eBay - the marketplace is too huge to want to go anywhere else. I purchased something on eBid but the seller had forgot he listed the thing there so eBay all the way.
So i guess Ebay is the winner.
Apparently, we can explain it by saying that Ebay was the first site (i think, correct me if i'm wrong about that fact) that offered buying and selling from all over the world by formats like "buy it now" or "auctions".