The $93 is a per-shipment US Fish & Wildlife fee for all legal exporters of wild game product. So it's on 1 piece or on 100. Unfortunately it is passed on to the buyer- through the purchase contract, it's not a tariff "surprise" situation when the package is delivered.
I would have to pay this before the package is even cleared to go the the regular Customs/Port-Of-Departure process.

This only applies to wild/trapped product that requires some sort of license, so horse hair, goat, pig, cowhide, etc do not fall under the aegis of USF&W and do not require inspection (and the fee) by them.