Quality of life here in Doha can be good. You certaintly should at least consider this. Of course everything depends on salary. Remember it is all tax free in Qatar! The Canadian goverment is getting none of it! :)
I would make sure that I understood what accommodations that they are providing. Health care, school fees if you have any children. If they are providing a vehicle or not, and if not, is there an allowance for such.
I've been living over seas off and on for over 10 years now and wouldn't change any of my experiences! Learning new cultures is a great thing, keep in mind that it isn't for everyone. I know several ppl that hated living away from home. I think that it depends a lot on how open minded you are.
Most things do cost more here then they do in Canada, but nothing that most of us can't handle. Good luck to you!
Charlene