I've seen many of your posts that would suggest to me that you're a highly qualified teacher; however, I think you need to bury your complacency and, well, wake up and smell the coffee.
Your advice to Linda suggests to me that you too are selling yourself way to short. More qualified teachers in China need to stand up and demand more pay; otherwise, the dividends will remain static and it will become more and more difficult for those of us with the necessary experience and qualifications to earn what we should rightfully be learning.
No, you don't have to be teaching physics to earn a good wage in Beijing. I've earned as much as 16,000 there. Yeah, I'm earning mush less than that now but at least I'm not living in what was, for me anyway, one of the most inhospitable environments on Earth.