What is value, and who determines it?

Your kids lumpy pencil holder is valuable to you. To me, it's a child's unskilled art project. What makes it valuable?

I spend 8 hours making a chair, I think it's worth $1200. You can buy a chair for $50 from Ikea. Why is my chair worth $1200, and why would you give me $1200 for it?

Now, where it gets interesting, is my examples are one offs that have a definite amount of time, material and energy that went into them. What do you do with a digital object that can be reproduced indefinitely?

If a digital object took me 8 hours to make, is it still worth the $1200 I'd like to get in exchange for my time?

What if 1 million people see it, should they each pay me a fraction of a cent? Could one person pay me $1200 and everyone else gets to consume it for free?

What if only three of the million that see it think it's valuable to their life, how much should they pay?

Are there other things people can do that provide me value that aren't monetary?

Could they promote my work or repurpose it or make artwork for it?

Is their labor in support of my work valuable?

How do you determine value when it can be copied indefinitely with no additional cost to you?