What is the distribution of wealth in Saudi Arabia?
There is minimal distribution of wealth in Saudi Arabia. Oil Barons and the Royal Family are extraordinarily wealthy and average citizens are in a difficult financial situation.
The question should specify whose GDPs per capita Saudi Arabia and Iran are being compared to. If it is the other Gulf Countries, the large relative populations of Iran and Saudi Arabia dilute the petroleum wealth in Saudi Arabia and Iran in GDP per capita calculations relative to the smaller Gulf Countries.