That's a chance anyone takes when bidding on previously owned jewelry which doesn't have tags. I've won auctions before on stuff that's broke the day I got it, and that's the chance I took. Reason why I my start bid so low as well, if you want something expensive and has all the proof, I know there are lots of auctions on here for the new stuff and some used, that may be more to your liking and may also cost a bit more.
I am also a trusted Listia seller, and my feedback shows by what I've auctioned. I have no reason to lie to exaggerate an item. I state what is is, etc and if someone wants it, they can bid, if not, that's Ok too.