in europe, it works this way: you buy the product from overseas (US or Asia) the shipment will be held by customs at the airport, or harbor and it will be determined what kind of product it is, how much value is declared etc. .This will lead to the calculation of taxes / tariffs and customs fees. The delivery service will collect the fees upon delivery (sometimes you can pay online). The vendor does actually have not to care about any tariffs in other countries.So the prices shouldn't change at the web shop. Maybe it's different with the US?