Yes, the rate of exchange to get the next level up, due to cost, just minor improvements that people can do without for another year, is what all smart phone makers have to face.
My S7 was $732, purchased Mar this year, so I have no need trading it in for 3 or 4 years. I kept my S4 3 years.
The improvements have slowed to a virtual hault in the last year give or take, by all manufactures.
Verizon pushes the 24 month payment plan, over pay in full up front, with an incentive that saves you money over the payment period, of about $100. At the end of two years, the monthly bill drops by $32....like paying off a car, don't want these payments anymore for a while, I'll keep what I've got.
We'll see when Q3 number are reported, who is number one in market share.