What is the value of 1979 dollar?

A circulated1979 Susan B. Anthony Dollar is only worth face value. An uncirculated one with the mintmark P or D (found above her right shoulder on the obverse) is valued between $3 and $20. A proof coin (denoted by an S mintmark, for San Francisco) is worth $10-$125. Values are dependent on grade, mintmark and varieties.

Values according to 2009 Red Book Guide to United States Coins.