I have finally talked a friend into upgrading to a new T650. He is on Cingular but under no contract. He wants to add the T650 to his plan under the $9 family option to his wifes phone. Any recomendations to the cheapest way to do this?

Bait and Switch?
Amazon seems to have the best deal on the T650 but only with new phones. I noted on my cingular page it has an option to "switch this phone to a add a phone" option. Has anyone bought under a "new" plan like $39 then successfully switched that phone to a $9 add on with another plan on your bill?