Ron Guth:
The 1822 Dime is a very popular date because of its small mintage. However, this date is even rarer than its small mintage figure suggests because other dates (such as 1809 and 1811) have smaller mintages, yet collectors do not consider those dates as valuable as the 1822. A quick peek into the PCGS Population Report shows that PCGS has certified fewer 1822 Dimes than any other date in the series. In Mint State, no other Capped Bust Dime date is as rare as the 1822.
Only one die variety (JR-1) comprises the entire Dime output of 1822.
As already stated, Mint State 1822 Dimes are very rare, though they cover a range from MS62 to MS66. The best example is the PCGS MS66 from the D. Brent Pogue Collection.