I have been a EBay seller since 1997 and this has always been a problem but has gotten worst as more people find out how to play the system. I sold a lot of USB miners and then my BFL singles. Always holding my breath but I did put on my auction that buyers needed to have at least 10 positive feedback and canceled a couple winner bids because buyers did not have it. But anymore since a seller can not leave negative feedback to a buyer the whole feedback system sucks. There are ways to protect yourself as a seller and one way is never have your bank account linked to PayPal or EBay. Get a very low credit limit Credit Card or I use my Discover Card and have had Discover stop unwarranted charges. So I pull my money from PayPal as fast as I can and leave no money in the account. The only way they can force my refund is thru my Discover and you can stop a charge back. I used the no refund on the auction and this was always going to be my way out with Discover and they will fight PayPal for you.
Edit: also always ship USPS that way the buyer has committed mail fraud and if you really get pissed you can file a complaint with the postal inspector , just file using the buyer and EBay. That is what needs to happen to put a stop to this!
I did that same as you but eBay will actually send you to collections very quickly if they can't collect from your credit card. I filed a complaint with CA State AG and hired a lawyer to sue them for dereliction of duty. I ended up getting the collection removed and it cost me about 80 hours of time, but I probably cost eBay/Paypal well over $30K in legal fees.
I haven't sold anything on eBay in ages. If I ever come to the point where I think I want to sell somethingon eBay I just donate it to a charity
Wow I am glad I never had anything get to that point of collections. My last lawsuit I was involved in spanned 10 years and cost me @$100k in attorney fees and tend to avoid them if I can. I think I will try and sell on Craig's list and deal in person with cash!