Does not neccessarily have to be done that way. It could also work like you pay for Kagi in country X, and get it localized for that country, using that language and prioritizing sites in that country and so on
Not that this couldn't be changed to the detriment of the service, but just to note: it's currently a feature to localise your results to any region
As someone in the EU/Schengen, I need results for 3 languages or 4 regions (if "worldwide" counts as one region) on a weekly basis. If a Dutch payment method would mean getting only Dutch results, it would be about as valuable as a newspaper with all pages about trade and international affairs blacked out: you'd need to buy it for every region you're interested in which probably surpasses the original price
As someone in the EU/Schengen, I need results for 3 languages or 4 regions (if "worldwide" counts as one region) on a weekly basis. If a Dutch payment method would mean getting only Dutch results, it would be about as valuable as a newspaper with all pages about trade and international affairs blacked out: you'd need to buy it for every region you're interested in which probably surpasses the original price