Back when I was at school, one of the subjects I studied was Economics. And one of the concepts it used was called “perfect competition”.
It was hard to comprehend – we’re talking well before the days of the internet here.
The idea was that consumers had “perfect knowledge” of what things cost to produce and that the supply of people selling products would drive the cost down to near enough exactly the cost of production.
Skip forward from my school days in the 70’s and we’re pretty close.