ive been to asia recently and there are alot of fake/immitation iphone cases, most notably:
more-thing
element vapor
mophie juice (the battery boost case)
and i recently ordered a case off ebay and compared to my legit case i was able to tell... the packaging looks legit, its even got the screen protectors and the right stickers, but they are missing certain things on the case here and there... of course if you dont have the real thing, u wont be able to compare it...
just sayin, be careful and you do get what you paid for... you WILL care that your case is fake when it breaks in half on you or something
that being said, paypal does protect you from fake cases...