Cost of Living in Riyadh

Hi guys, can someone assist me in the current cost of living in Riyadh these days?

We're a family of 3 (one 8 yr old child), and have a middle of the road lifestyle with some weekend splurging and some weekends doing 'broke entertainment'... and we've lived as expats in the Middle-east for over 10 years (UAE, Kuwait, Oman and now potentially a move to Riyadh).

The categories I'm looking at are:

- Groceries
- Eating Out at Restaurants
- Entertaining at home (I believe you HAVE to do that to survive)
- Retail Therapy
- Average Cost of Rent-a-car per month (4wd)

Any range or approximates are welcome.... just trying to figure out at what point will i save (because accomodation and education will be on me and not the potential employer)