My first ever purchase on Ebay was a pair of Sunnies, Oakleys, seller swore black and blue they were genuine but even cash converters could tell they were fakes! It was quite a rigmarole to get my money back, I had to get proof that they were fakes, some sort of documentation and I think I had to post the lot to paypal in the US or wherever it was at the time. In the end I only got refunded 75% of what I paid, which is better than nothing.
Needless to say I've since made a few purchases and sold a lot more stuff via ebay. Albeit I'm a lot wiser as to what I purchase.
The funny thing is often when I've looked at things on ebay as a buyer looking to buy something, most of the time I can actually find the item cheaper in a real store (be it bricks and mortar or online). To give you an example you can get vacuum bags directly from Miele, a packet for $20 with free shipping. On ebay you pay $20 plus shipping for the same thing!
Anyhow what I hate these days is that you pretty much have to use Paypal to trade on ebay. And if you don't you'd be surprised how many people will send you a paypal payment to your email with a non existent paypal account when you have clearly stipulated that you don't have a paypal account and payment is only direct deposit or whatever!!!
I'm also all too weary of scams where people claim never to have received the item as well.