It is a very good offer.
A two-bedroom apartment will cost you around QR 5000 per month. Food expenses would be around QR 1000. Add another QR 1500 for miscellaneous expenses. The rest should be in your pocket. School fees vary from school to school and from country to country. If you are from an eastern country, it should be around QR 2000 per month per child but at schools managed by western nationals, it is much higher.