Are you sure you don't mean 15,000 for housing. That figure is more in line for a monthly payment for a villa or apartment of the size that you will need for your family. I have never heard of such a low housing allottment for a family.

1500 is a little low for a car but definitley workable. Finally paying 20% of tuition costs could take a far portion of your husbands salary as school tuition here is very expensive. You have two school age children and will eventually have 3 school age children.