Hi yusraarifa, I think your husband's pay offer is good but not great (assuming he has around 20 years experience or more; if he has less than 20 years, its awesome salary). I am a civil engineer too, and know quite a few design managers working on roads & infrastructure projects. The salary is in the same ballpark as your husband's, varying from 50k to 65k per month. If your husband wish to discuss anything about Qatar's work in the field of roads / infrastructure, feel free to send me a PM.

For a big family like yours, monthly expenses can be something like:

Rent - 15k - 18k for 4 bedroom unfurnished villa in decent area of Doha
Food - 4k
School Fees - 3k per child
Utilities - 1k

Rest should be easy saving. However, a few things you need to worry about. Weather is terrible, and its difficult to get admission in schools.

Cheers