How Competition Regulates Market
How it works
If there are multiple items competing with one another in a business people will almost always choose the cheaper choice. This means that in order to stay on the market the more expensive ones will be forced to lower their prices because people aren't going to spend more than they have to on an item.
Examples of markets with no competition and how they were run
Rockefeller oil industry in the 1860s was a company owned by one man, John D. Rockefeller. He took over all oil sale and production to where there was no more competition left. This meant that he was able to still make a profit by raising the price of oil to an absurd amount because it was something that people needed no matter how expensive it was. Rockefeller took advantage of that.
High Gas Price
No one will want to come here if there is a cheaper option and they will be forced to either go out of business or lower their prices.
Low Gas Price
The one that is regulating the market. People are going to come to this instead of the expensive one, which will force the expensive one to lower its prices.
Phone companies
You have the option to buy a galaxy from amazon or one from samsung. The samsung one is $750 and the amazon one is $370. You're going to choose the amazon one almost always. This is how regulation works. If no other company besides samsung was selling these phones, then they could raise the price probably to 1,000+ dollars, but they can't because there is compatition.
Walmart and All Other Convenience Stores
Walmart is forced to regulate their prices to not an insane amount because of the amount of other stores that sell the same products for a decent amount. Walmart has to stay in the business so they set their prices just lower of the competition, and that is how they are regulated.