Actually, the Chinese tend to buy whatever is seen as 'cool' (in their opinion, which can be odd). I saw many iPhones a year or so ago, they were the 'hot' product then. They aren't as loyal to the brand as many in the US as it's not a Chinese phone of course.
Then HTC was 'in', and everyone was buying those. These days they seem to be all about the newer, bigger ones. I've seen a lot of Samsung's, both SIIIs and Notes lately, for some reason. No doubt it will swing back to Apple some when the new one comes out.
The price of an iPhone here is usually about 4-6k RMB, depending on what model and where it was made (eg: HK or mainland). A shiny Samsung S3, by comparison, is about 4-4.5k RMB at the moment (I've been looking, 'cos I'm going to buy one). The price is also different depending upon color!
As an aside, the Apple store that has been in Lido hotel* for ages has been replaced by a Samsung one! I laughed.
*Lido hotel is a very well known, high end, 'laowai'/business hangout here in Beijing.