Cost of an iphone 4s plan with AT&T?

I really want the iphone 4s, and I have Att. I've never owned a smartphone.

How much would it cost per month if I had an iphone 4s contract? I need to upgrade soon anyways, so would I get a discount for upgrading/ contract?

Ok, so here it is broken down:

*Cost of the iphone 4s with upgrades/ contract/ etc.
*Activation fee
*As much Data as I can get with a plan, or the rate at which it's calculated
*Unlimited texting
*little to no calling

Initial cost:
Monthly cost

It depends on the plan you want, including texting and data. I would talk to a representative from AT&T