You may be right but without actually seeing a QF payslip it's hard to compare because of the apples and oranges factor. When a QF guy says he earns $180 000 a year as an A330 FO I'm not sure if it includes his super (which is far better than ours) or just what appears on his group certificate for the year. In any case we don't have fleet pay and we are comparing QF FOs with EK CAs at this stage. We haven't even got to QF CAs.
Don't think that there aren't any taxes in the miraculous middle east either. They are many and varied.
I would agree that the wage cost to the company may be similar between both companies because they pay for housing, utilities, schooling and some other bits and bobs. Unfortunately this doesn't help your average sand dweller because it doesn't end up in his bank account.