You might be better off buying a bargain lens from KEH than one marked EX+. KEH rates their lenses by cosmetics only. A bargain lens may have a little visible wear but you're sure the lens has been used and is probably a good one. I have only bought manual lenses from KEH but rated as EX+ doesn't guarantee the lens works. I've returned EX+ lenses where you couldn't even turn the focus ring. A couple of the bgn lenses I bought really didn't show any wear at all. I've never had one with a mark on the glass. In any case there isn't much concern with returning a bad lens to KEH. If it is faulty you give them a call, explain the problem and they'll email you with a prepaid RMA you hand over to the FedEx shipping counter.