Most 1964's are worth only face value- it is the largest mintage year of nickels. I usually find at least one 64 per roll.
However, you're on the right track- if you find one in good enough condition, with a strong mint strike, you have value. A "full stairs" nickel in MS condition is worth a premium.
I think it's funny how a nickel of such large production can be worth so much if it's got the stairs.
I can't tell from the picture, but your stairs might not be complete from one end to the other- keep hunting!