Depends on so many things.
If you are getting a package from your employer where your accomodation, kids education, trips home, electricity, and water is paid for, then considering the 0% tax rate you can save bucketloads. As soon as you are paying for accomodation or education then that takes a huge chunk out of your salary.
For a guide you can stay in outer Dubai in a Villa for around 50-60,000 dirhams (don't know what that is in other currencies) per year rent. If you want to live where the rich people like to live and be in Jumeirah (beachside suburb in Dubai) you'll be looking at 100,000 dh's for a villa. You will pay close to 30,000 dirhams a year per child to go to a good school.
So as you can see education and accomodation are the killers, but as I said if they are included in your employment package I say you can save heaps here. Food is reasonably cheap, beer and alcohol in general are on the steep side but not ridiculously expensive. Anyway good luck.