David,
Here are some ballpark figures:-
International schools (you need teaching qualifications, i.e. a degree in education or equivalent)
From 20000 in a 2nd tier city to 50000 for the American School in Guangzhou
Local schools - foreign experts (usually white, unfortunately) - from about 7/8000 in 2nd tier cities to 22000ish in some Shanghai/Beijing 1st tier cities.
Local schools - local teachers - 2000-5000, depending on size of city and experience.
So, you should really be expecting/ holding out for at least 7000 and probably 8000 plus perks as a starting salary. Also it is important to check that you will get a Z visa. Many schools want to avoid paying the new National Insurance charges for foreign experts, so they may try and palm you off with an F visa (not a working visa)
A friend of mine with no teaching qualifications last year got a job in a school in a small city, starting salary 8000, so go for it. Get offers from other schools and play them off against each other.
Good luck