Cost of Living in Riyadh

Hi ronaldp, a good way to look at it would be to see if your savings here are potentially greater than they would be in Dubai. So consider the major expenses:
Compound housing: anywhere between 6,000-20,000 SAR a month. The lower end will get you a decent apartment in a smaller compound with few facilities/activities,  and it won't necessarily have a large western expat community.  The more a compound has to offer, the more expensive it gets.
Schools: the three co-ed international schools (British, multinational and American) start in the 30,000-40,000 SAR per year. They increase as the grade level increases. Nurseries/preschools tend to range from 1,800-2,500 SAR per month.
Housing and schooling are truly the biggest expenses here. People in the bigger/better western compounds usually have them provided through work, or at least have a very generous housing allowance. Most companies provide some sort of school fee allowance.
The day to day cost of living is not bad, mostly because there isn't a whole lot to do/spend your money on. Shopping in the more expensive supermarket for all your groceries is unlikely to reach 1,000 SAR per week for a family of four. Eating out can be on a par with Dubai. Mobile phone costs similar to Dubai, petrol is cheaper here. Uber/Careem makes getting around less painful to the pocket. 
Hope this helps. Feel free to drop me a message if you have any specific questions.