I teach at a boarding school. Most of my kids are tuhao who can't speak English above the third grade level. I'm completely serious when I say that in an average A-level class of 25-30 students, only around 5 are fit to be there. However, when those five students get accepted to some obscure university in the UK, it's a great feeling. That's what keeps me going.
The great thing about teaching outside a tier-1 city is that it's completely mercenary. There is a French guy in my town with no qualifications who makes 3k more a month as a French teacher than a former IELTS examiner with a DELTA degree at the same school. He knew he was the only French guy around, so he went to valuetown.
I imagine you'll probably get screwed over your first year. I'm not sure what somebody with your qualifications should make...I only have a bachelor's degree so we can't really compare...but you should get at least a 3k housing allowance, on top of that a low 5 figure salary with a reimbursement of your round trip flight upon completion of your contract. This is for 16 40-minute classes/week. Most contracts have you paying the cost of getting your Z visa (~$250 if you're a US citizen, much less if you're not) but the school will pay for your physical examination and residence card.
I'm sure most of us on the forum had a crappy first year...but things get better when you start getting the hang of things. Don't get mad if you get a bad deal your first year, just get them back twice as hard your second year