Long story short, my girlfriends iPhone got destroyed in hurricane Ike and can't afford $400 for a new one. However, her mom recently switched to AT&T about 2 weeks ago and is still within her 30 days to return her phone. Can we have her mom return her phone and purchase an 8GB iPhone at the subsidized rate, then my girlfriend can use it with her service? We'd then mail her mom a regular phone we have to use. Will this work? Or does AT&T require her mom to have the 3G data plan at the time of ordering over the Internet? There is one other option... I also have an old iPhone, so if I activate that old one on her line (formerly 3G), then go to Best Buy and try to purchase another iPhone 3G Best Buy will see her account has the old iPHone, will they let her upgrade?