..... for $30.00

My daughter plays this game and if you have kids that like to game in mmos then it might well be worth it. Normal month to month payment is $5 a month.

http://www.massively.com/2010/07/15/free-realms-offers-lifetime-sub-for-a-limited-time/#comments

It has a free to play element but with reduced playable classes and some content restricted if your kids want to try it out. Made by Sony Online Entertainment.

http://www.freerealms.com/