Here is a rough idea of monthly costs:
Rent - QR12,000 to live on Pearl or in a big villa somewhere else
Car - QR2,000 Rental or installments for a decent SUV
Food - QR2,000 Basic groceries for the house
Education - QR2,000 I don't have kids, so I'm guessing here
Going out - QR2,000 This is random. You may spend way more, or way less

So that leaves you with QR15,000 left to save - approx CAD$5,000. There are no taxes here, so if you think that's more than enough, come over.