It's widely believed that US carriers pay a lot for the iPhone. A perfect example is Sprint which signed an estimated US$15 billion deal for the iPhone and won't make money off the handset until 2015. AllThingsD presents several compelling reasons why Sprint and other US wireless carriers are willing to accept such high subsidies for the iPhone.
First, the carriers believe the iPhone will help them attract customers and keep them for the long term. Second, the carriers won't stop selling the iPhone now because they want to capitalize on the demand for the LTE iPhone which may arrive as early this year. Third and final, each carrier signed a multiyear agreement with Apple and can't change the subsidy terms until they've rode out the contract.