>> they are spending their wealth on the national budget there
This is a good point. The Saudi's are rethinking many parts of their economy and attempting to get off of their own dependency on oil by making drastic changes:
The role of foreign investors in the economy has always been a controversial issue in Saudi Arabia, which follows an austere version of Sunni Islam. Yet as oil prices plummet to around $30 a barrel, authorities are racing to find alternatives to revenue from crude exports to finance a budget deficit about 15 percent of economic output.
The slump in oil prices has already pushed Saudi authorities to cut spending, issue more debt and draw down the kingdom’s foreign-currency reserves. Officials are also weighing plans to sell stakes in state-owned entities from hospitals to airports and even Saudi Arabian Oil Co., the kingdom’s biggest oil company, known as Aramco.
There's talk that in 5 years the Saudi's could burn through all of their foreign currency reserves at the current rate.