How do you determine the value of a thing?
Normally, in our free-market (or heavily regulated free-market) economy, we think that the value of a thing is set by what people are willing to pay for it.
If I’ll see you my collection of neckties for $10,000, and you’ll pay $10,000 to buy my collection of neckties, then we know my collection of neckties is worth $10,000.