It's not going on now, but from mid summer till about 10 days ago, people were using
www.live.com and getting cash back for "buy it now" listings on ebay.
Example: Lots of Losi 8ight 2.0 Buggies selling for MAP - $649.99. At one point, you could get 30% cash back for starting your search for your new losi buggy on live.com. You pay $649.99 up front and then Mircosoft would give you $195 back to your paypal account. I know it sounds like total BS.... ask around, read around, lots of people got some killer deals. I even saw some ebay sellers putting a description of how to do this in there listings.
Bottom line is you would see people paying full retail for stuff you could get much cheaper at online hobby shops but when you factored in the live.com cash back, the deal would blow everything else away.
Obviously this doesn't account for all the strange stuff we see on ebay but defineately some of it.
Go to
www.live.com and click on the link on the bottom right of the photo named "Save with Live Search Cashback" for more info. Like I said above, the ebay deal is not active right now, but keep an eye out for it to come back.
