1979 P Susan B Anthony Dollar value is face value for circulated coins. If the coin is uncirculated and not certified they’re worth $1.25 to $2 each.
If graded MS65 by either PCGS or NGC then they’re worth $10 and in MS66 they’re worth $20. 1979 Susan B Anthony, or SBA, are not silver but clad copper – nickel.
Look for 1979 Wide Rim variety
Mintmark: P (Philadelphia, PA), D (Denver Mint), S (San Francisco Mint) on the left side of the obverse, just above Anthony’s shoulder.
More Susan B Anthony Dollar Values: