How much is a 1872 Trade Dollar with the mint mark S and in F-12 condintion worth?

The first Trade Dollars were minted in 1873. If your coin says Trade Dollar on the back and is dated 1872 it is a counterfeit.

If it does not say Trade Dollar, then it could be a genuine Liberty Seated dollar. You should have it inspected by a dealer or certification agency because its value could range from $300 to $1000 depending on condition.