Cell phones...schmell phones

OK Techies. I need your help.

Our old 3G iphones are falling apart (cracked cases, etc.). We are looking into upgrading but the costs of a new Iphone 4/4S and signing a new two year contract seem outrageous. $200-400 upgrade price WITH a two year contract for $120.00 a month.

My little 3G is hanging in there, so I would keep it and just give Charles a a new phone, but the Iphone 4 is interesting to us because then Charles can use Facetime to see the girls when he is at work. This is a key feature for us, but not necessarily required.

Is it possible to get a pay as you go, Iphone? We have wireless at home, so data isn't really an issue. But I text often, and make calls about 450 min a month. I want to spend $75.00 or less for two cell phones if possible. Am I dreaming?