Does AT&T charge to activate an iPhone?

I ordered an iPhone 4 on eBay and I'm confused as to what I should do to activate it. Do I just take it into an AT&T store and have them activate it? Also, does it cost money? Approximately how much would it cost? Please answer! Xx

The mistake you made here is that you bought an iPhone.

http://www.google.com/...m/nexus/4/

(Anyways, no they don't charge to activate)