Hi,

Just to add a bit more information to the first reply. A QR20,000 a month salary (people, please do not take this the wrong way it is said in the spirit of reality and difference of requirements for people from different parts of the world) for a British expat is not allowing for much especially as it is all inclusive.
You have rent and utiltities to consider. Although there is some indication that this is coming down, reality is that you are looking at about half of your salary given to this.
Car loan is another major expense. Your wife may need her own car or have to rely on taxis which is another expense to consider.(public transport is in its infancy yet)
Food prices in Doha are very high, I would say if you do a fair bit of home cooking with the occassional treat you are looking at Qr2000 a month at the very least. (nappies and formula etc may add to this figure)
Don't start me on schools, its a nightmare getting a place and $$$ to pay for British Schools.

Going back home is also an issue, although at the moment the pound is at an all time low, reality is that you have to spend many riyals to get a few pounds and a few pounds don't go a long way in the UK. Take into account you may have monthly mortage repayments and other commitments, summer holidays, if you have a place to stay, transport, food etc while keeping up the payments here.

I really am not trying to discourage you to come here, but I would want to have a clear picture if I was in your situation. The best thing may be to try and renegotiate your contract for accomodation and schooling as a given even not an allowance, even if it means taking a little less as basic salary. Also if an option to come out here for a month is possible taking leave from your exsisting job, to get a feel of the place before taking the plunge.

I wish you all the best with whatever decision you make. Feel free to ask anymore questions lots of people will have a better idea than myself.

Goodluck.