What is the value of a 1934 US quarter?

First check the back, under the eagle, for a tiny "D" mintmark. If it has one, your coin will be worth more than if it doesn't. Numismedia lists the following retail values as of 1/2013:

No mint mark:

Very worn condition - $5.00

Moderately worn - $8

Slightly worn - $9

Almost no wear - $10

Uncirculated - $22-150 depending on how well-struck it is.

D mint mark:

Very worn condition - $5

Moderately worn - $10

Slightly worn - $17

Almost no wear - $75

Uncirculated - $218-2200