The people I know here who have masters degrees in education have all found pretty good jobs at private schools, although all of them complain that the “system” sucks, i.e. management. There was a thread here recently about a private school called Kang Chiao where a lot of the pros and cons of private schools in general were covered. Each school kind of has its own (twisted) culture, and you just have to find one that you feel you can work with without going crazy.
However, the most decent paying gigs are the schools that are waaay out in the sticks. You might find yourself stuck in the mountains if you’re looking for a better than average salary.