NGC population is 16 in MS67, with none graded higher. PCGS population is 30 in MS67, 7 in MS67+, and 2 in MS68. My guess is that at the time of the auction, Feb., 2014, this MS67+ was the highest graded example, and at least two people wanted it very badly for their registry set. Unfortunately for the owner, when it came time to sell, the price had dropped substantially. That same $9,988 coin sold for $646 on Jan. 4, 2017.
The $800 price is much too high, also. An MS67 should be closer to $300 - $400, and an MS67+ about $500 - $600. (and, honestly, I think those prices are way too high, too, but if a buyer wants a coin badly, it is worth whatever they are willing to pay.)