I think you are comparing apples to oranges (no pun intended )
How many flagship phones does apple release in a year? How many Android flagship phones come out in a year?
There are no 3rd party Apple phone manufacturers, Apple has 100% control over pricing, where as on the Android side of things there are plenty of manufacturers all releases new phones throughout the year and one try to beat the other in terms of hardware specs so prices of flag ship phones drop literally within months of being out, because well they are literally only flag ships for a month or so.
Samsung alone just sh1tes out new phones during the year, and there are many other manufacturers, like HTC, LG, Sony, Motorola, Google (Nexus).
Apple doesn't have to drop the prices because if you want an Apple phone you have no choice but to buy it from Apple, if you want an Android phone there are plenty of choices if one manufacturer is too expensive.
So Android phone manufacturers not only have to compete with Apple also compete with each other on the pricing front.
Steam: SpectralMeat