The scarcity of the 1866-S Quarter Dollar can be blamed on its small mintage and the dearth of coin collectors in the far West. Because so few nice examples have survived, this is one of the condition-rarities of the series. However, there is one outstanding example that sets the standard for this date -- a superb PCGS MS66 that burst onto the market in 2008 and set a record price of $97,750. The next most valuable example sold for less than a fifth of that price, underscoring the desirability of this exceptional example.
The majority of the 1866-S Quarter Dollars examined by PCGS have been circulated, with most of those examples scattered fairly evenly from VF20 to XF45. In AU and better conditions, this date is a true prize.