Advice on job offer

Hello,

I have received a job offer in Beijing (teaching) for 12,000RMB a month with free shared accommodation, totaling 38 hours weekly including hour lunch breaks.  I have never seen any serious ads for a salary any higher than this, although I sometimes read comments that would lead me to believe that some teachers manage to make quite a bit more than this.  Methinks they are tough-talking without any real idea of what they are talking about, for the most part. 

I have 120 hr. TEFL, teaching observation, a Bachelor's, a semester each of TA-ing for a professor and working at a Montessori summer program, and work experience as a senior analyst at a financial company, which I kinda hated.

So I would like to know how the offer compares to others, and whether it is feasible to do better.

On a related note, is it worth it to instead take a lower paying job (with free housing) that figures out to a higher hourly pay rate, and then pick up private tutoring gigs on the side? Can you reliably get tutoring jobs? 

The thoughts of knowledgeable people are greatly appreciated.  Thanks!