Hm....as a ebay seller, I would have to disagree that eBay sucks. However once something like this happens, ebay basically says "yeahhh...". Just be careful as a buyer/seller... basically in order to use eBay correctly you have to know what your doing Paypal, fees, relisting, return policies, feedback, confirmed address, confirmed account...all that stuff and you'll be fine.
But as for your situation...looks like you just got really unlucky with jackass buyers! I bet eBay will suspend/ban their accounts...don't think nothing will happen. It's not ebay that sucks...it's basically the stupid ass buyers/sellers out there