I think it will be easiest to assume that value is subjectively assigned to property and that property is created according to Locke’s Labor Theory of Property. That is, someone labored to create something and therefore property was brought into the world. How much value was brought into the world might be subjective and something left for the market or committee to decide, but there was no property before someone labored.
Now you might think “wait a second, I value trees and birds, but nobody labored to create those things”. That’s correct that these do have value for us, but they are not property and therefore have no market based value. The value I am referring to resides only within human society as property.
But what about the value of a technician, like a plumber repairing a leaky pipe? There is no property there to his labors, yet his services can be very valuable to us. I would argue that his labors do create property in a repaired pipe and the person pays for the service the same way that they would have purchased a new pipe. Generally the purpose of a repair service is to re-generate property that is broken and do it for a price that is less than the original system. If these services were more costly than an equally new system, then there is greater efficiency in obtaining a new system and the technician’s labor has less value to us. The point here being, all value is in reference to property.
What if I go to listen to a singer sing a song, surely there is no property and therefore no value there? Well this is getting into the controversial idea of intellectual or non-physical property. A singer creates their property in the formation of the song and delivers it’s value to people if only just in that moment. The only way we know that property was there is because of the value that was left behind.