I think we are being a bit tough on the coin. All 3 of the 1890s CC dollars are good dates, and not as available as the 1882-1884 CC coins, with which we are all familiar. Second, as a MS 66, the pop is 45, with 11 66+ and 1 67 certified by PCGS. Third, any toned CC dollar is far more uncommon, as Carson City has a hot, dry climate—less conducive for intense toning. I have a feeling it could still go big.
It seems like enough potential buyers saw the previous lower graded holder and didn't bid strongly. The person who got the upgrade still likely did well.