What is the value of a 1947 US half dollar?

1947 is a common date for Walking Liberty halves. Numismedia lists the following approximate retail values as of 02/2010:

Very to slightly worn - about $8 for its silver content.

Better conditions:

No mint mark (Philadelphia):

Almost no wear - $22

Uncirculated - $36 to $2,020 depending on quality

"D" mint mark (Denver):

Almost no wear - $26

Uncirculated - $46 to $2,150

W "mint mark"W on the front is the monogram of the coin's designer. The mint mark position is on the back.