I have only experienced three negative encounters on ebay through the entirity of my membership. Here is one which happened quite recently and feel it would be useful to share.
I recently purchased a dvd from a seller in the last few minutes of the auction, so no other bids - bargain price.
A mistake on my part, usually i only deal with sellers who accept paypal, unless it is a specific desired item. But like i said it was a last minute buy and i must have skimmed the terms.
I sent the cheque which may i add, the seller requested immediate payment within 3 days (which i found odd as they would only accept persobnal cheque/cash in the post)which i thought may be unlikely considering how tempramental the royal mail can be!
Anyway, long story short, the cheque was cashed and the item was never received. A couple of days later, ebay banned the seller and they werent responded to any emails. Also ebay informed us there was nothing they could do since they were no longer registered - which as you can imagine angered us.
The one thing we found odd was that when the invoice was sent via email there was an austrailian address yet the cheque had to be sent to a uk address.
It wasn't the money which was so much of an issue, as like i said it was a bargain basement price. It was more the issue of who else had they done this to?, how much money had they scammed? and how many people get away with this?
So my advice is, just beware not all sellers are as they seem!