Why a low cost iPhone makes sense

A more affordable iPhone 5 with a plastic case could make sense. T-Mobile is getting rid of subsidies this year and they will be carrying the iPhone for the first time, if you couple that with emerging markets I see a definite market for a different iPhone model. Perhaps they will sell this more affordable iPhone model unlocked at T-Mobile, and online in emerging markets, while sticking with the current "Free"/100/199 subsidized model at traditional carriers.