But as Rob pointed out, ebay is totally skewed toward buyers in these cases.
That isn't completely true. In my only experience opening a case against a seller, I actually lost. I got some figures that reeked of cigarette smoke, and the seller had described them as "great condition", "mint condition", etc. Never mentioned any odors. The seller offered to take a return, but wanted me to assume all shipping costs (around $20). I thought that was BS, and since the item wasn't as described I would open a case with eBay. Well, eBay decided that cigarette odor matched the "used" description and that I merely didn't want the item, so they ruled in the sellers favor.
I have read a couple of similar stories over the past year or so of buyers getting shoddy items, but losing "not as described" cases because of the "used" tag/description. I'm sure that is the exception to the rule, but dealing with eBay as a buyer CAN go both ways.