Let's analyze your offer step by step:
First, your accommodation: I would suggest you go for the company's accommodation. This will save you from the hassle of looking around for one and then furnishing it. Also, whenever you decide to leave the company, you will again save yourself the trouble of selling off your furniture.
Second, a major cost you may be facing is school fees. If you are a westerner, school fees is high. I have very little idea of what it's like. You may need to do your own research on this.
Third, you may be getting to spend say around QR 2000 per month on your groceries and miscellaneous items such cost of internet, petrol etc.
If you deduct the above from your package, you will get a rough idea as to how much will remain in your pocket each month. You can then decide to accept or reject the offer. As for the negotiation part, I cannot say anything on this matter. Each company has its own policies. But for Qatar Airways, I believe they must be having slabs for each grade and probably they may not be willing to change their offer unless you are something very special.