You walk up to the bar and order a beer for $5.00us. The bartender looks at you and says, why do you pay that price for beer? There are drops of beer right there on the bar, which you can have for nothing!

You say, “there aren’t nearly enough drops of beer on the bar to serve my purpose, and it would be way too much work to gather it all, even if enough drops were available. I have no use for drops, I need a full mug. I’ll just pay the $5.00, please.