If you can’t know the price, you don’t display a wrong price, simple.
You either geo-locate, or maybe put the minimum E911?
In EU these kind of sheenings never happen.
Airplane sites tried with payment fees, adding 40/50€ for ALL providers. EU changed the law that the price has to include the fee for at least 1 payment… So if the cheapest is paypal at 30€, they have to add 30€ to the price.