do what roessnakhan said.
i checked and mine is $200 (price of phone on contract) + $250 and i got mine november 2011
so yours should be $450 too
It doesn't seem like that option is available for everyone. I used to have that option, but not anymore. I did use that on one of my lines in January 2011, but that should affect my ability to use it on my other three lines.