I've seen those auctions, pretty sure they just go down to the beach, they'd be fine if you were feeding them to a mantis or something but they just won't last in our reef temps. It's too bad.
The lfs had the ones that I bought on accident, they were shipped to them mislabeled, and they didn't know. They kinda took a hit on them. I watched them pull like 25 empty shells from their tank.