Ron Guth:
The 1913-S Dime is regarded highly because of its low mintage. At 510,000 pieces, the 1913-S Dime has the second smallest mintage of the entire series (not counting the ultra-rare 1894-S Dime) -- only the 1895-O Dime has a smaller mintage. Not surprisingly, the 1913-S Dime is hard to find in circulated grades, but it looks like a good value when compared with other dates with larger mintages (such as 1897-O, 1901-S, 1903-S, and others). In Mint State, the 1913-S Dime is only slightly rarer than the "type" dates because collectors put aside ample quantities of nice examples. The typical Mint State 1913-S Dime will be either MS63, MS64, or MS65. Only in MS67 does the 1913-S Dime become a condition-rarity.