The common market rate ifor the total package is somewhere between 80 to 300K USD range depending on your status. If you got the local package, the rate could be slightly lower. I also saw expate getting 350k plus housing, child education, tax equalization, hardship allowance and bonus achieving about 700K USD. (Yes, 700K.), which I personally think the expat is totally over-rated.
As a bench mark, you can ask for around 10-25% salary increase from whatever you are making, plus tax equalization (20-30 USD), housing (30 uSD), child education (20k), and some travel allowance. If the package is less than 1 million RMB, don’t call it an expat pay.