Saudi Arabia has a lot of its people being paid off, in all kinds off government hand-outs. This is very expensive. To fund this the Saudi must sell oil at a fairly high price. There is a lot of anger in Saudi Arabia and to save off revolt the Saudi promise more and more to their entitled constituents. If there is a revolt in Saudi Arabia you can bet your ass the consecutive government won’t be as agreeable exporting oil for dollars as house
Assuming that the US government wouldn’t feel compelled to intervene in a costly military expedition when ever such a revolt would occur.
The Saudi Government can not meet these domestic ‘obligations’ if their oil sells at less than 86$ a barrel. And as the dollar decreases in value this number will increase, clearly. So if the dollar crashes to a third its current value, the Saudi government will be effectively forced to triple the price per barrel of its oil exports.
You can’t win.