The offer is good if the benefits include schooling and accommodation. Not to keen on car because the Petrol doesn't cost much. I agree with the comments of having a different lifestyle here than in Canada and the initial settle is a bit of a struggle. But I do have quite a few expat friends on that pay scale and they save more than any western world. If your wife can find some thing the day cares arent as expensive as Western world.

Yes people like living in Pearl or West bay but if your intention out here is to save money then you can rent a decent 2 bedroom in Doha for 6000-7000K. The only thing I want you to consider is job risk. Its a very dynamic world and falling Petrol prices are not helping the situation. Projects start then put on hold and redundancy is not far.I know a few who quit good jobs in Canada and UK to come here but ended up losing on both sides.

Evaluate the project well before signing !! Good luck