Where To Purchase Low-cost IPhones?

Battery life- iPhone four affords a talk time of 7 hours on a 3G community and 14 hours on a 2G network. The standby time of iPhone four is 300 hours roughly. Its counterpart iPhone 3G s is having a standby time of 300 hours and is offered with a talk time of 5 hours on 3G and 12 hours on 2G. While