If I choose to buy land, goods, services, the seller chooses the "value". If I agree on the value, I have free will to to purchase the land, goods or service. If I do not agree on the value, I can either offer a lower price, or walk away.
If I purchase said land, goods or service, and later decide that I no longer want those things, I can choose to sell them. At that point, I set a value. If the purchaser agrees on the value, I then sell/transfer ownership to that person. If the value has grown since I purchased said land, goods, service, I could potentially profit. If the value has not increased, I am at a loss.
So, to directly answer your question about "authority". (In my case, land that was owned, and worked, for 100 years in an area that no one wanted to live). A price for said land was agreed upon. The sale was advantageous for the seller as he no longer wanted to tend it. I assumed the risk, taxes, etc. Working said land was extremely arduous. Shepherding it through multiple hurricanes, floods, etc bore a financial burden. Many years later, as the area began to develop, my asset grew in value. Selling it produced a profit. This profit allowed me more ability to purchase other land, goods and services.
As I'm tying this, I'm certain you're aware of these basic economic principles, but simply don't agree with them. Disagreement is fine. But this is the way things are done in my country. And, I choose to live here because I agree with those principles. If I wanted to live in a country where an entity could come and confiscate my wealth, and redistribute it, those countries exist. I could likely move to one of them.