This is the kind of issue that eBay has been combating since 2008, allowing consignors to hype coins by citing Coin World or PCGS values for lots that exaggerate worth.
The above coin has many flaws, from probable cleaning to bag marks and scratches. It is not worth $12,000. It’s only our opinion, but we place worth at about $50.
Compare it to a real MS66 courtesy of CoinFacts (which every auctioneer should subscribe to for latest values and data about every US coin).
As for grading companies, and knowledge about which are reputable, see this article by numismatist Susan Headley.
Some auctioneers know better and still hype worth. This is hypothetical, but imagine how an unsuspecting buyer would feel taking a coin that may be damaged to a dealer to make good on the investment, only to learn that the coin was worth a few dollars over silver melt?
We have been noting how eBay has made the playing field more level in recent months. Check this earlier article on Proxiblog.
The best way to combat hype like this is for each bidder to make a decision on whether to patronize Proxibid sessions that hype coins. We know what we’re going to do. Do you?