One penny each, two for four cents, five for a dollar
My son and a friend of his were trying to waylay pedestrians passing by our friends' house and sell them 'tie-dyed' pieces of facial tissue stained with green marker and water. The pricing was: one penny each, two for four cents, five for a dollar.
On the drive home, my son was totally impervious to the idea that you might buy five individually to escape the dramatic markup on volume. He was willing to admit that you might buy one for a penny, and then buy one more for a penny. But the idea that you might buy five in a row ran up against his rule. No, if you want five, you pay a dollar!
I remember being similarly impervious to market forces when I was his age, despite my own father trying to make the same point. To me then, and to my son now, it made sense that if you were getting more, you paid more. More for more. We didn't realize that people try to get the lowest unit price. Kids have their system, and their rules, and they want to have people follow the rules, even if it doesn't make economic sense.
The mom of the friend gave the pizza delivery guy, on top of his tip, an extra dollar to buy from them. He paid a dollar for one sheet.