The 1923-S is the rarest of the 3 Walking Liberty Half Dollars issued between 1921 and 1929 from AU and up. Common up to AU where it then becomes scarce. At MS60 to MS64 it becomes rare, leaving gems at varying levels of extreme rarity from MS65 to MS67. Frosty luster and certain levels of toning can be found somewhat easily. Beware, the strikes for this date are very weak with rare strongly struck pieces bringing premiums.