I've had three somewhat similar experiences in the past two months - two by a guy in the UK and one here in the States. I have cut my Ebaying way back now. I just don't want the hassles. But I've been screwed by a tradesman standing there looking me in the eye as well, so it isn't an Ebay only problem. It's a greed coupled with incompetence problem, IMO.
It's too bad we can't make an "I've been conned by..." list here. Thats what the feedback is supposed to be on Ebay but it doesn't work at all. Some people cannot be pleased no matter what and other people are extremely aggressive. Who needs it?
I just pay everything via Paypal using a credit card. Then, if Paypal won't reverse the charge, the credit company will do it in a heartbeat, at least in the US. Australia is different and I don't know about UK credit card companies.
But if I get my money, I move on!