I'd provide another reason

According to my friend who is the owner of an architecture design company and a real estate company, the salaries (not the grey income) are actually increasing at 20%-30% rate per year in China.  This is how his employees are paid.  A midiocre designer with 15+ years experience can earn 500-600K RMB/yr in salary. In fact he was talking with me about hiring in US. A sub-branch bank head (I used to work in Bank of China and know sub-branch head does mean much in a bank) in first line cities earn 1M in salary (note: this excludes grey income).  He gave me some other counts.  Even myself is very concerned with the house marker there, I value his opinions and consider it makes sense.  After all, he sees more and deeper on site.