Ron Guth:
The 1904-S Dime is scarce because of its low mintage of 800,000 pieces. The PCGS Population Report shows substantially more 1904-S Dimes than the larger-mintage 1904's, but that is because of the higher value of the 1904-S in most grades. Balance is restored, however, in Mint State, where the 1904-S is much less common that the 1904. The usual 1904-S grades from MS62 to MS64. Gems are very scarce, with only small numbers of MS65 and MS66 examples known to exist. Two of the best examples were from the Eliasberg Collection (now in a PCGS MS66+ holder) and the Bob R. Simpson Collection (also in a PCGS MS66+ holder).