Any economic concept has an (allegedly) rational individual at its basis, and the whole science of economics studies human behavior, namely, the part involving interactions about limited resources
It has greed and fear at it's core which is not irrational, they are survival instincts that humans depended on for hundreds of thousands of years.
The market only organizes it in a quantifiable manner, it doesn't add nor subtract anything.
I think you are confusing the 'market' with the 'consumer' ? is a well defined concept which I stick to here
In a free-market economy, prices for goods and services are set freely by the forces of supply and demand and are allowed to reach their point of equilibrium without intervention by government policy, and it typically entails support for highly competitive markets and private ownership of productive enterprises