Im posting here cause i cant find an answer

Ok so i have a main EU account that i play WOW on and i wanted to play on NA servers so i made an NA starter account using the add account feature and now to add game time im not sure if i should buy EURO cards or DOLLAR cards to pay for my NA account because when i go to buy game time it switches me to the NA store and i cant afford to buy both and try cause well i dont have the money
Would really love some clarification
Thank you.