How much is a 1928 silver dollar with e plribus unum?

The National Motto E PLURIBUS UNUM is on all Peace dollars and does not add to the value of the coin. What does add to the value is if it has a mintmark or not and the condition of the coin. In circulated condition a 1928 Peace dollar with out a mintmark (only a "S") is valued at $293.00-$456.00 with out the mintmark value is $17.00-$89.00