We are an IPhone and AT&T family. We've been with AT&T for years and no issue. We LOVE IPhones. Here are reasons why:
Mine is the oldest version from when they came out originally. I no longer carry my laptop when we travel because I have all the access I need with my IPhone.
Hubby has a middle of the road version (8/09) and LOVES it. We are in business for ourselves and our Iphones keep us in constant email, phone and text with each other and customers. We HAVE to have access fast with our business.
Daughter (15) is has the newest, latest and greatest version. Her original one was stolen at school. LOVES it with all the apps, texting, etc. She has a good case for its protection.
We wouldn't switch to anything else.
As for pricing: hubby has his own account with higher minutes and unlimited texting, and data plan. Monthly charges are around $170.
Daughter is on plan with me. We both have data plans (me:$20, her:$40), unlimited texting ($30), lower minutes (1400) Our bill runs right around $190 a month.
The IPhone does not have a "warranty" but you can buy a 2 yr plan for $70ish. This did come in handy when daughter dropped and cracked an IPhone and instead of paying full retail price to replace it, we paid $199.
H. that helps. Again....we LOVE them and wouldn't get anything else.