I must get involved here and give someone's view from another perspective. I don't know if I have been very fortunate, or very lucky, as I have dealt with ebay as a buyer for a few years, and have never suffered any bad experiences. The only hiccup was when someone sent me a batch of items and there was only half the quantity there (only cost a few squid). No reply from the seller, so I contacted PayPal, who sorted things with the seller, who then contacted me with an apology for not replying, told me to keep the items that were sent, and he also refunded my payment in full to my account.
I scan ebay every day, looking for those little items that I wouldn't be able to afford normally, and within a week or two of searching, I usually find what I want. I am a bit devious in that I use a last second snipe bidder, and I win a lot more than I lose.
I have noticed a great decline in private sales, and a large increase in shops, some using real underhand mailing costs to get the full retail price for the item.
But on the whole, I have never had any problems with sellers or PayPal.
I have never sold anything on ebay, so I can't comment on that part, as I normally give things away to the needy, rather than sell them.
Bogs