A few months after Apple released the first iPhone, they cut the price by $200 because…well, we don’t know. It could be that sales were below what they expected, or it could be that it doing better than expected an they (and/or AT&T) wanted to build on the momentum.
Either way, the fact that the retail price of the phone was subsidized by other revenue streams is part of what made the price cut possible.
I note that a similar opportunity exists with the new Apple Watch, which plays an important role in Apple Pay, their new mobile and internet payment system. As Bloomberg reports, Apple Said to Reap Fees From Banks in New Payment System.