And contrary to what most think about the big site stifling competition, it actually gives users a fighting chance to sell their items in an easy and convenient way, where they normally would have had no way to do so.
If you really want to make money with eBay, check out the eBay Developers web-site. You can use their API to make a mash-up. Here is an example I made: Buy It Nearby
. PM me if you need any help getting started.