As I said in another thread, you can live cheaply in Japan if you're about 20 minutes by train from Tokyo.
In that thread, someone said that rent is expensive in Beijing and Shanghai. It looks similar.
Anyway, in China I heard that if you go to hospital in a different household registration, you have to pay the full medical costs. It sounds the cost of living in China is expensive.
It's true that rents in Tokyo are expensive, but Kawasaki or Adachi, where the commute takes about 20 minutes, are cheap.
I don't know about the salary, but I checked X or blog and it seems that some are work in the US headquarters, but none in Beijing.
Anyway, when are you there? It looks you are talking in 2010.
I'm not good at English, so I don't get the nuances that native speakers do.