No matter how you word it, the pricing model must take subsidies into account.
Carriers can't just give away phones. They have to build in enough monthly profit to guarantee that they can pay themselves back for loaning out the money in the first place.
For example, AT&T's stock took a drop last year when they revealed that they had paid out something like a half billion dollars in iPhone subsidies, and that it would take about 18 months from the start of each customer's contract, to pay their share back.
Yes there was a report on this. The subsidy price of the iPhone was so high, profits per share were diluted by $0.20/share.