Your whole premise is incorrect. How limited do you think the number of companies is? What makes you think they collude? How many companies would need to be in on the collusion? Generally, collusion among companies is very difficult if there are more than 2 or 3. You would need LOTS of companies in on this collusion.
I also wonder who is forcing him to buy gas. Some consider it a need, but in reality, it is a luxury. Unless you drive 30 minutes or more to work, you could ride a bike. if it is 10m, or less, you could walk.
People survived for the vast majority of human history without gas, why is it necessary to have it now?