The website says 10 USD for 10 eRyos, but it also mentions 1 R$ = 2 eRyos.
Given the current currency exchange rate, 1 USD is roughly 1.97 R$.
So a donation of 10 USD would exchange to 19.70 R$, which would exchange into around 38 eRyo ingame.
Correct me if im wrong, I have to translate the website to English, so I might have missed something.
I realize there are transfer and exchange fees, but they do not justify the difference in value.
Why would I pay in USD if I could get a much better deal exchanging it into R$?