Sprint's SEC filings have revealed that the carrier has committed to purchasing $15.5 billion worth of iPhones as part of the long-promised $20 billion gamble. If each handset costs around $630 at trade, then we're talking about the network holding nearly 24 million units. Given that the company most recently ate a loss of $1.3 billion, most of which was caused by carrier subsidies for the 4S, there's a
