Ron Guth:
1850 saw a return to the big Dime mintages of the past, this being the largest since 1842 (at New Orleans). As a result, the 1850 Dime is one of the more affordable dates of the No Stars type. Mint State 1850 Dimes are fairly plentiful, particularly from MS62 to MS64. Gem examples are about as tough as any other date in the series, and MS66 seems to be the best possible grade. Proof 1850 Dimes are extremelty rare and fewer than ten examples exist today.
Jerry Fortin has identifed twelve different die varieties for this date and suspects that more will be found over time.