akia: Depends what you're doing. If you're going CDMA prepaid to XT prepaid I believe it should be free. If you're still have some term left on a plan with CDMA and moving to XT there would be some termination costs.
Try getting your friend to put his number into this website and find out what upgrade options he has http://store.telecom.co.nz/mobile/upgrade
JarrodM: My Mate was going from cdma to xt and they said it was $20 for the sim plus another $20 to get the number put on. is that right?
$20 for the sim - Right