What is the value of a 1938-S Washington quarter?

The 1939 Silver Washington Quarter was minted in Philadelphia and San Francisco. According to USA Coin Book, these are the values of this coin:

Philadelphia (no mint mark): In good condition, this coin is worth about $6.55 up to about $95 in MS60 mint condition. In MS65 brilliant uncirculated grade, it is worth about $225. Proof coins were also minted here. In PR65 brilliant proof condition, it is worth about $430.

San Francisco (small "S" mint mark): In good condition, this coin is worth about $7.60 up to about $105 in MS60 mint condition. In MS65 brilliant uncirculated grade, it is worth about $260.