Why i have to paid twice for the same game?

[surrel]

I know that in other games this will be stupid. But this is a MMO and SE let to do this on FFXI, you can buy game and expansions for PS2 and can log your account on friend's pc client.

Maybe that's the case but it's not uncommon in this day and age for video games to try and make more money. Certain games won't even let you play split screen co-op anymore. You have to buy 2 copies of the game if you want to play together with a friend.