I was going to say 6,000 is the standard, but given they want 18 hours per week and that China has undergone rapid inflation in recent years, I think this is rather low, I would agree. I wouldn't teach 18 classes a week at a public job for anything less than 7,000 or even 8,000 rmb per month. The apartment included should have EVERYTHING working. Airfare more than covering what it costs to go home and travel allowance should also definitely be included.