For expats, from what I am told, it depends on what you are teaching and the level of the university.  My friend is a professor at a top university and he earns 15k per month plus he was given use of a private house on the university campus.  Another one I know makes about 8k and gets a small apartment.

For locals, I think the pay goes between 6-20k depending on their specialty.  Plus, teachers also get bonuses based on their student grades.  And then, of course, there are the red envelopes they get from parents and students for various 'reasons'.