Hold on Kenster...
Petrol is an essential things for basic living?
Housing (shelter) is non-essential?
Yes, petrol (or oil) is a basic essential. Like air, we don't notice it when it is there, but stop it for one moment, we'll die.
The main use of oil is for transportation, to move goods from one place to another.
It is used on diesel trains to move coals from mines to plants to generate electricity. It is used by farmers on farm machinaries to produce and harvest food. It is used by trucks to move food and other essential things from farms to processing plants, and to distribute the essentials to all locations around the country where people live and buy. It is used by oil tankers to move oil from oil rigs to refinaries. It is used by trains and buses to move people to work. It is used for cooking, for lighting cities, to generate power in offices, to run computers...
In short, without this transportation, the basic structure of our society will collapse back to stone age when communal living started.
Oil price is exhorbitant during crisis time because of the severe devaluation of paper money and oil reservation for government and essential use.
Due to the worthless nature of paper money, oil seller wants gold but buyers can't pay because they are all broke. Any available oil will be reserved for basic transportation and the army. Only a small portion is made available to consumers who are eager to fill their tanks up, pushing retail price sky high.
As with the Bretton Woods II, I can see the birth of a new international currency for international trading pegged to gold, since USD can no longer serve this purpose.
Housing is non essential in hard time because it is low in the order of survival priority, well below energy, food, water, and electricity. People will grow well sleeping on a couch but they will die without the other four. When people needs shelter and can't afford, they can stay with parents, friends or even squat.
We will see a lot of squatting with implicit government approval.
(In the US, defaulted home owners are allowed to stay in the house)