Will try and add my 2 cents here.
USA phone contracts are a rip off compared to the rest of the world.
We get charged both ways for calls, text etc, not like most other countries.
Will tell you what i did.
I bought my non jailed I phone from abroad.
if in the USA you can find these on ebay also, just buy from good dealer with lots of recommendations on past sales.
You can get from AT&T and T mobile many pre paid plans, with sim cards.
Like for instance you pay AT&T 100 usd, the credit is good for 1 year under the go phone plan and pay by the minute. .20 cents a minute. for talking.
Don't use the phone for data unless you are connected to free wifi and you wont be charged for data coverage
Many places with free wi fi now.
There are ways to beat there system, but takes a little extra effort on the users part.