This is exactly what I mean when I hear people spouting off about something they know SFA about as if it is fact. Come on Woland.
Moving a family from what is a classified as a Grade A country to a Grade C country (in terms of adjustment to a new way of life, culture, food, schooling etc.) involves a massive increase in salary just to persuade a family to take the chance on a move. For Shanghai there are a lot of factors to consider (all of the above plus ethnic background of the assignee, marital status, number of children if any, whether the spouse will be working or not, how it will affect their career path, etc.). For Shanghai the salary increase could be anywhere from x2 to x5 based on those factors and the specialisation of the assignee.
It isn't just about the difficulty of life there, it's about the upheaval and change in everything that the assignee (and family) took for granted. It's why most MNC's have psychologists on hand to help with the adjustment. Culture shock to a family is massive, and so is reverse culture shock when the time comes to be repatriated.
It seems you are looking more at the difference in culture/lifestyle between Shanghai and Saudi whereas that is only a small part of the picture.