Price of 'payment solutions that can be used with'

I have an (quite) old site for an artist that maybe wants to sell his images online because of Corona. ( )

Does anyone know if there is a provider I could use that has a low 'starting level', since he might not sell too many?

Since it is a Norwegian shop, I guess I must use a 'European provider' ?

Thanks a lot

Do I understand it correctly that it is no 'fixed' price, just a percentage of every sale?

(That would be super)

afaik yes