The worst I have had happen to me as a seller is sometimes the buyer was a little slow in paying. I can not say the same about sellers.
If you buy at a flea market or a pawn shop, you can look at it. If you do not like it you walk off and are out nothing. On eBay you are at the sellers mercy. If he does not describe the condition of the item accurately, you are at best out shipping, and I can eat for a week at the price of shipping these days. When I sell something the only warranty I give is that the item is as described, or I will refund your money and shipping both ways, why should you have to pay for my mistake? As a buyer, I expect to be treated the same way. If I lose anything because the seller was dishonest or just stupid, I will give them negative feedback. I do not even hesitate to file a dispute anymore. It used to happen maybe one in twenty times, now it happens about one in three.
On the other hand, I merely find it amusing when the seller says he doesn't know anything about what he is selling, so it is being sold as is, for 10 times what it is worth. Why? Because I am not going to bid on that item, so it does not bother me at all.