What is the value of a 1935 E buffalo nickel?

The letter is an F rather than E but it's not a mint mark. It's the initial of the coin's designer, James E. Fraser.

Mint marks were on the backs of nickels until 1964. The mint mark, if any, is under the Words FIVE CENTS.

Please see the question "What is the value of a 1935 US nickel?" for more information.