The market for cheap phones is much bigger than for the expensive ones and as you see from the Apple numbers: the expensive market is pretty much covered. Also covered in an separate environment form where those users are reluctant to switch because it's hard to learn again.

imho I think that fighting for the low budget Android market makes much more sense than for the high price Apple audience as "Apple" has become the "I can afford it"-message of prestige this group is looking for and therefore won't be replaced by anything else. Even if you buy the most expensive Samsung, you'd have to explain how expensive it was first to your audience. There is no need with Apple. Everybody knows you've spend a lot of money on it.