How much does a Big Mac cost?

Imagine you go to a McDonald’s, order a big mac and when the cashier tells you it’s $10 (I’ve got no idea how much it costs) you say: hey, it’s too expensive, it costs you a dollar to make this burger. I think I should pay you $2. People don’t do that (I hope…)
Who cares how much money costs McDonald’s to make the hamburger? What matters is the value people get from it. People pay based on what it is worth.
A note for freelancers: it’s too easy to fall in the trap of the how much it costs to make. So, are you charging based on what it costs or based on what it is worth?
Big difference.