Things for Chinese teachers are changing now. I just had a conversation with a Chinese teacher that told me ten years ago he earned half the salary of a foreign teacher. Now we earn the same. I can see by his nice car that he is not lying.
If you do the math, about half of the teachers earn more than some Fts. One teacher told me that every summer she earned 30,000 Yuan charging every student one hundred Yuan per class at her home. Add to that a housing stipend, summer pay, bonuses for test scores, and end of year bonuses and some of these teachers do really well. On top of that factor in those expensive school banquets parents throw for teachers. It was quite nice when one parent gave me a 500 Yuan gift card at one of those things.
For one particular teacher, after we did the math there was only a 10,000 yuan difference between his salary and mine. I did not dare ask him how much he earned for his summer school and expensive dinners and gift cards. Except for housing, I do not get any of those other bonuses.
When I first came to China, I felt sorry for Chinese teachers. Quite a few complained to me about my salary. When the next day I saw them driving into campus with a new car, I became suspicious. Too nice of a car to buy with such a small salary. I then spoke to the head teacher trainer in town and he told me that my salary of 5,000 a month was in the middle. So what teachers tell you that they earn, add 30 to 40% more and you are getting more at the truth.

I am sure the T.A.s earn little and teachers in small country schools earn pauper salaries. But those in better schools and cities are doing better than before.