marxism

this video is a pretty good and intuitive explanation: https://youtu.be/xzqm9QHls60

In a very simplistic explanation, it costs money to keep workers alive and working. That means that it costs "money" to create a product that requires work. That imbues the product with some value, the abstract cost of producing it.

But that value is not necessarily the price. If a product is very scarse and desired, it might sell for way more than was required to create it, generating profit for the seller (be it an artisan or a capitalist). It is generally assumed that this profit will generate competition, which tends to reduce the price back to something closer to its value.

On the other hand, if something is too underconsumed that it's market price is lower than the cost of producing it, the corporation will either go bankrupt, stop producing that product or lower wages (or fire people) in order to recover some profit.

In either case, the price of commodities can fluctuate around their labour value, but it serves as a baseline for that price from which there can't be too much consistent deviation.

That means that the value of any commodity is dictated in part by the cost of maintaining and operating capital (which I haven't described here), and in part by the absolute minimum necessary to keep the workers alive and working.