Will my monthly phone bill be more expensive if I buy the iphone 5s?

I have the iphone 5 right now with AT&T, I am planning in buying the iphone 5s when it comes out on Friday at the apple store. I'm not sure if buying this phone will raise my monthly phone bill or if there's any other payments I'll have to make besides the $200 to buy the phone

No it's not any more monthly. But the iPhone 5s is only $200 for new customers, or those who are up for upgrade. Otherwise it's $549

It should be the same price