The original mintage of the 1923-S Monroe half dollar was very large by commemorative standards as 274, 077 coins were minted and sold to the public at $1.00 per coin. There were so many of them that they initially had little value over their face value and many were spent during the 1930s. Consequently, today the Monroe is one of the silver commemoratives that can be found readily in circulated grades. But interestingly, the Monroe is relatively rare in Gem MS65 or better condition. During the early 1970s, the Monroe was one of the least expensive silver commemoratives and I remember very nice mint state coins being available for $20 to $25. But today, the Monroe's rarity in MS65 or better condition is no longer a secret and these Gem specimens are among the more expensive in the silver commemorative series.
The typical Monroe can grade anywhere from AU to MS64. MS65 examples are very scarce and Superb Gem MS66 specimens are definitely rare. The design of the Monroe is very flat. This leads to problems with strike and also attracts numersous handling marks and abraisions. A well struck, mark-free Monroe is definitely a premium rarity for a silver commemorative. Luster can be very frosty and of course toning can be present in varying degrees.