What is the value of a 1941 Walking Liberty half dollar With W?

The West Point Mint did not open until 1988. You're looking at the monogram of the designer, A. A. Weinman.

In 1941, there were 3 coins minted - one was plain and the other two carried a mint mark of "D" and "S." The mint mark location is on the back around the 8:00 position.

Please see the Related Question for values.