QR 20,000 is good salary to live in qatar. As only u and wife u can get a small flat around QR 4,000 & living expense depend upon ur life style vary from 1,500 - 4,000. Car rental is 2,000 avg for good saloon car & loan if u going for small car, loan payment will be from 800 to 1500 depends upon number of years. so atleast a month u can safe upto 6 to 8 thousand.