I'm surprised that the iPhone has any significant market share in China. I would expect Chinese users to prefer phones from Chinese brands running Chinese-developed ROMs (albeit based on Android, minus the Google proprietary bits). Is the iPhone's hardware design and/or iOS really that much better?
Chinese people go crazy for iPhones, when the 6 was released my friend had a trip scheduled to go back home to Shanghai for a few weeks, EVERY ONE of his friends asked him to bring them one (or more) unlocked iPhones, and they were happy to pay well over store price, as the iPhone got released a month late there.
He ended up bringing them only for his closest friends, as otherwise he would have been arrested at customs :)
There is a substantial status aspect to it (your average Shanghai fashionista wouldn't be caught dead with a xiaomi), but Android UX still has a bad reputation even in China. The group I'm in of Beijing-based Chinese techies (I'm the only foreigner) are largely split 50-50 between iPhone and various Androids (and no WP even though the company is Microsoft). They aren't very fashion oriented (programmers, researchers).
An iPhone 4 bought refurbished, then used gingerly for 2-3 years is within reach for many. Seen plenty of waiters and taxi drivers using iOS. It's not like they're all getting maxed out 6 Pluses every year.
If anything, one's phone is used so much that it's a reasonable thing to spend money on, even if you skimp on paying for data plans and spend less on other things.
