AT&T Upgrade. Basic phone eligible for iphone 5?

Upgrade is in 2 months and I have a basic phone (no data). Am I eligible to upgrade to an iphone? Do I also have to upgrade my plan and pay for data? Is there a way to get the iphone but still keep my basic phone and just sell the iphone?

I'm not an expert but to my understanding is that they would just give it to you because you have just a basic phone. You'd probably have to pay for the iPhone and yes you would have to upgrade your plan because they wouldn't give you data for free. And no i don't think they would give you the phone just so you could sell it. If you tell them you want an upgrade they are going to turn off the basic phone and turn on the iPhone.