When a brazilian user is making a payment, Paypal will only take the payment if the currency is BRL (that's why the profile edit page asks specifically “are you brazilian?”)
The payment page converts from USD to BRL by using a fixed rate of 1USD = 2BRL.
This is obviously wrong, FS should somehow get a current rate from somewhere trustable.
Also, that screen does a bad job at telling the user about the currency. So the user might freak out for a while when he sees his $30 offer appear as a $60 (sorry about that @mvallebr !)