You have stressed a "nice" place several times and added that you would like a place where Western expats live. In Doha you won't find a "Western" area, we tend to live all over. Villas tend to be at least 4-5 bedrooms, usually more, and the nicer ones are 25-30K. Compounds have three or four bedrooms and run around 12-20K. Apartments in "nice" high-rise buildings have fewer bedrooms and can run 12-15K (or more.) SUVs are the same here as in the US and interest rates run about 8% (yes, they will tell you 3% but add it up!) Internet is quite expensive, up to 600 QR/mo while mobile phone plans are dirt cheap. Gas is a steal and food is about the same. Same price at Chili's and Applebee's as in the US but the hotel restaurants are sky-high (and the food usually mediocre.) Remember you have to pay taxes back in the US - at least state and local if and when you qualify for the "foreign domicile" tax exemption (generally that means you cannot spend more than 35 days in the US/year.) It sounds like you will be making about $90,000 US per year here. While that's certainly enough to live a nice life-style, it isn't enough to have what you've stated you'd like IF you want to save half. Sorry.
Mandi