I typically avoid these auctioneers with deceptive naming, I suspect shenanigans. "No association with any government agency"
For that matter, the legitimate "state surplus" auctions on eBay seem to get bid up absurdly high. It's as though people assume that anything coming from the state must be a hidden treasure, even when the listing explicitly says something like "appraised as circulated and cleaned".
Recently I saw a news story that the state was auctioning off a bunch of unclaimed property and there were a lot of coins in the lot. I took a look though and the starting prices were way over the value. Like they'd have lots of foreign coins starting at over $100 and I'd see a few silvers and mostly junk bin stuff. It definitely was not priced to move.
Those sites are frauds, here's another one: Property Room. Just read the complaints registered against them online. http://www.propertyroom.com/c/coins
I wouldn't look at these sites. The only police/govt auctions you should check out are in person. I read about some guy who accumulated hundreds of bikes at cheap prices, or many skateboards are acquired for fire sale prices. But this probably doesn't happen online