One of the perks of living in a third world South American country like Brazil is that the only thing keeping me from making purchases in the Argentina eShop is making an account. I made a couple of purchases (Cuphead and Celeste) today there for the price they're asking for just Cuphead, while on sale, on the BR eShop.
One of the many bad things about living here, though, is that PayPal charges a fee (6.4% + a fixed fee) for transactions from abroad. Were it otherwise I'd help you guys asking for a favor. Have you tried getting a prepaid international credit card or Nintendo eShop prepaid cards?