There are so many fakes on there, it totally spoils it for all the genuine sellers. It's very difficult to identify from the pics if they are fake and they all bear the Pandora hallmark now. I don't think you can tell by the sellers feedback as lots of buyers don't even realise they are fake until it's too late and the coating wears away or you have it cleaned and they all end up patchy
I've previously needed up with fakes but last week I tried again with two retired charms, it wasn't easy to identify but they were fake and all went back
I also purchased a bracelet that turned out to be larger than the size stated. It was too big and I had hassle returning and certainly didn't see why I should pay for return postage, when it wasn't as described.
So I've had it with Pandora on EBay unless they are able to do something about it. The ridiculous thing is the price the fakes sell for, mostly well over half price, just a few pounds less