http://www.playonline.com/ff11us/event/sep2007/
For the past few years, many players have requested a feature that would allow them to change their World server at will. Now, starting in early summer (June or July), players will be able to move full accounts (up to 16 characters) to the World server of their choice for 3000 yen. This price is lower than the amount charged by many other popular MMOs.
There are no restrictions on an account's first move. However, to prevent RMT-related problems, players must wait 90 days before emigrating to another World.