Anywhere from $1.00 if it's not in mint condition, all the way to $250.00 if it's never been circulated. The guide for grading Buffalo Nickels is as follows:

ABOUT GOOD / AG =Coin can be identified by type. Date is only very slightly visible and very weak. Rim is worn away.

GOOD / G = Buffalo's horn is not visible, completely worn away. Date and all lettering must be readable although well worn. Has at least part of the rim.

VERY GOOD / VG = Half of buffalo's horn is visible.

FINE / F 2/3 if buffalo's horn must show. Rim on obverse (front) side of coin is complete.
VERY FINE / VF = Buffalo's horn must show completely but will be well worn in spots. Brush of buffalo's tail at hip will not show small art work details. Indians cheek bone will be worn but slightly visible.

EXTREMELY FINE / EF = Buffalo's horn must be complete with at least 1/3 of horn very strong and not worn smooth. Ribbon on Indian's braid will be very bold and will show a trace of small art detail work at the middle of the braid.

ABOUT UNCIRCULATED / AU = The tip of the buffalo's horn must be easy to see. Small detail lines must show on brush of buffalo's tail. Only a very amount of wear on Indian's cheek. A large amount of hair on buffalo's shoulder must be easy to see.