I think eBay's rule changes have made it more appealing to scammers. Before there would be repercussions. Now there really aren't any. So it attracts them. For example you don't find this problem at all on Amazon (or at least if it exists I've never hit it, and I use Amazon *very* heavily).
I still buy a ton of things on the internet, all my origami paper for example, and I have stellar experiences. So I think there are still great companies out there. You just have to pick and choose.