OK, that's a good challenge, let me take a stab at that. In the US we consider middle class to have a home, college for kids, 2 cars, meals out, nice vacations, going to see grandma once a year, new clothes for school, $ for extracurricular activities for kids. The average family income in the US is around $50,000 and that's a little low for all the above. So, a wild guess would be around $75,000 year plus housing and schooling and car allowance and airfares. Expenses are high in the Gulf and your kids' friends will be from families that make a lot more.
Mandi