Chances are that he applied for a lower grade position than his experience qualify him for. If so, then it was a decision he made and the company cannot go beyond a pay level for that grade.

That said, is money the only reason for you to move? why applying for work in this part of the world when he is already working and getting paid? My point is that you as a family of arab origin is perhapse looking for a cultural element in that move. If so, then you may have to trade that for a lower pay, it is your priority which decide that.

If he is going for interview in Qatar, then he implies that he is semi-accepting the offer. Even if he negotiate, he will not move far from that figure. Best if he negotiate before going.