Cost of Living in Tanzania? (Dar es Salaam)

Hi, I'm in process of salary negotiation with a company in Tanzania Da es Salaam. What should be a decent salary if I stay their with a Family of Protected content
- I would need Protected content to be sent to India for some savings and expenses.
- 2BHK House at a safe and secure locality
- Kid's education in a good English medium school
- Return Air Tickets to India for me and family twice a year