I taught in China from August 2011 to June 2018, so my answer applies to that period.
First of all, I have taught in California high schools for more than 30 years, have a California teaching credential and am at the top of the pay table there… and am the exception to the comments found in this thread. When I took a job in China, I found a fairly lucrative position teaching AP English at a special AP center in a foreign language high school that paid me pre-tax 30,000+ rmb per month, plus gave me a housing allowance, medical insurance (reimbursement) and r/t airfare to California once (and after the first two years, twice) a year. There was also an annual 20,000¥ “completion bonus” after the first two years.
I was taxed at the 24% rate, which was not too painful considering the salary and perquisites I received.
China can be a terrific place to work if you get into the right setting. The Chinese people generally are good to work with (though you may come across the rare odd personality). Play by the rules, particularly when it comes to contracts and visas, and you should do fine. If you make around 10,000¥ a month, you will be able to live well, but try to get a job that pays for your housing, medical and r/t airfare to make it more comfortable. Oh, and be sure to make plans to do some traveling during the 3–4 weeks of Chinese New Year unless you enjoy listening to fireworks going off at odd times day and night for several weeks. Most expats travel at that time … just get your r/t tickets early – and avoid all surface transportation. Good luck.