$400 is the extra cash that you can send to AT&T sleepaway camp if you want the 3G iPhone but don’t wish to have anything to do with AT&T. The no-contract iPhones with sell for $599 and $699 for the 8G and 16G models, respectively. If you are already an AT&T customer and wish to purchase one but aren’t eligible for an equipment upgrade, they invite you to do so for for $399(8G) or $499(16G). Of course, if you’re a new customer, an existing iPhone user or are near the end of your current AT&T contract then celebrate by handing over the $199/$299 subsidized pricing. Plans start at $69.99 a month.