Its acceptable to pay real money in a P2P MMO for Character transfer, Character renaming, Character race or appearance change , Mounts and Minions.

But it is not acceptable to pay real money in a P2P MMO for extra storage and in game items, that's P2W.

even if i do accept to pay real money for an extra storage (which i'm totally against it) it should be one time, not every 30 days.