Couple things. GSM phones are cheaper because they have many manufacturers and require less powerful processing. But moreover, the developing world has a lot mo

Couple things. GSM phones are cheaper because they have many manufacturers and require less powerful processing. But moreover, the developing world has a lot more spectrum availability. Rich countries have 100 years of legacy, spectrum-inefficient radio technology they need to support. Indeed, the latest iPhone 7 actually comes in two models, one with CDMA support and one without. Sprint and Verizon (and other CDMA carriers) ultimately are going to shut their CDMA networks down and be LTE only. Same is true of GSM carriers; they'll be shutting down their 3G/UMTS/WCDMA support as LTE devices become available everywhere.