Cost of living in Cologne (Germany) is 11% cheaper than in Al Mubarraz (Saudi Arabia)
This comparison is lacking data. It provides a decent comparison, but it is not yet reliable. It is based on 233 prices entered by 30 different people.
For example, to keep the same standard of living that would require ﷼ 15,000 in Al Mubarraz you would need to make just about ﷼ 13,313 (€3,059) in Cologne.