Subscription price is 9gbp in the uk, this equals to 36brl.
http://eu.finalfantasyxiv.com/product/#usage_fee
This means that square haven't removed the regional pricing from all places, and they havent brought all currencies in line with the global pricing structure.
Thus the official explanation is suspicious as there are still places officially with a cheaper subscription
(Also this kills the "it wasn't intended the existance of the cheaper sub" and the "everybody should pay the same" arguments, since officially square enix is offering a cheaper sub for uk residents)