Your collector value on a buffalo nickel, just because they’re not made any more and aren’t in circulation is going to be higher than 5 cents. It’s still legal tender and can still be spent as a nickel. But the price someone will pay for it is going to vary from maybe 35 cents to $1,200 (or more) depending on the date and the condition of the coin and whether there is anything rare about it (like an error in the strking…one year, 1937, some D mint mark buffalo nickels had a 3-legged buffalo and the best specimens can fetch 20 grand). You have to know the date, the mint mark (which mint was it made in, D=Denver, S=San Francisco, P=Philidelphia), and if its a more rare date, most likely you’d want to have an expert “grade” the coin to tell you the condition. Look at this site for an approximation of the worth of what you have:
http://coins.about.com/od/coinvalues/l/bl-buffalo-nickel-values.htm