I pay Hetzner via PayPal, and I haven't had any fees attached. Online.net however charges a card directly so my bank does charge it as a foreign transaction and adds a percentage.
That's because they fleece you with the exchange rate. You're paying a many-points worse exchange rate, even against a stabilised market average.
For one recent actual example, Paypal recently gave me 1.339 USD for 1 GBP in a transaction. The raw market rate that day was 1.421. The week mean was ~1.410. Paypal already holds this cash, they're not exchanging jack on the open market.
A pre-pay FX card —shop around— would have given me $1.40/£ on that date.
Paypal work like a bookmakers. They cover the entire spread with very little risk. Nothing on Paypal is really free.
