first of all congratulation for your offer
, this salary not bad but also not very good
you need 5000 for rent
(for medium level of accommodation)
averge school fees is about 30,000 ryal for one kids (you can go for cheaper and also you can go for more expensive )
2000 ryal per month for car
for food it is not expensive
If you dont have better offer go ahead Inshallh you and your family will be happy here