The 1981-S is the third lowest mintage in the Susan B. Anthony circulation strike series. Only the 1981-P and D have a lower mintage.
Circulated Grades: In circulated grades it is easily obtainable and worth only a small premium do to its low mintage.
Uncirculated Grades: In uncirculated condition they are still obtainable in grades of MS60 - MS63 wit a slight premium over circulated coins.
MS64: In MS64 condition they become a bit more challenging but yet can be easily found.
MS65: In MS65 condition it becomes tougher to find and some cherry picking is needed to find them in this grade.
MS66: In MS66 they are very difficult to find and are considered somewhat scarce with only a couple hundred examples available in this grade.
MS67: In MS67 it is almost unobtainable. As of 2011, PCGS has only graded one example in this grade with none being higher.