Hi, Dusty --
Depending on the surface quality of your particular piece, the value could range from $385 up to $450+. Your coin will be worth closer toward the upper end of that value range if it has cameo/frosted devices and dark, mirror-like fields, whereas the lower price applies if your coin is a more typical example of a Red-Brown Proof-64 1874 Indian cent.
All the best,
Josh