Cell phone prices are a racket but as this article points out, most Americans are allergic to math.
My last cell phone cost me $140 up front and then $35/month (for unlimited data from Virgin Mobile) and I kept it for almost three years. My total cost was $1,260 for 32 months, or an average of $39.38/month.
My new cell phone cost me $200 up front but dropped my monthly cost to $24/month (joined my family on Ting). If I can keep it alive for the same 32 months, my average monthly cost will be $30.25. I saved $9/month by getting a newer phone on a cheaper plan.
A new iphone 6 on a two year plan will cost you $199 up front but will then cost you $92/month, for a total cost of about $2,400, or roughly three times what my new phone will cost. That's over $100/month averaged out over the (artificially shortened) 24 month contract life.
If you do the math on the actual monthly cost of your phone and plan, it rapidly becomes clear that what really matters for most people is what you pay for monthly service. The difference between a $200 phone and a $650 phone is suddenly less important if you're paying $100/month for service because you're getting ripped off so bad anyway. For people here, many of whom have $10/mo plans, the phone cost is relatively more important and paying $650 for a new iphone 6 doesn't make sense under any circumstances.