In 4500, u wont be able to save anything and also, ur groceries bill would be around Qar. 2500 ( for a couple) without any lavish spending...SO no lavish weekends at bars and other enjoyment. Look for a basic od Qar. 7000/- plus accomodation plus transport on behalf of your employer..if you are looknig for adecent living..
If u r desperate for a job,then off course, go ahead with the offer.