I will say not less 20,000- 25,000 QR assuming that your employer will provide you with housing,car and a round trip for you and your family.
Also, you should discuss the school fees for your kid.
I will also assume that your montly pay in the us is something like 6,000 $ after taxes. Which means you can technically be making the same money here and not having to pay for housing, which in my opinion will result in more savings.