At my seasonal temp job working retail:
The other night a woman and her mother entered the store. Immediately beyond the front door is a large bin full of flannel pajama sets we had on sale for 50% off of $16.99.
"Look, Mom!" the daughter said. "Pajamas are 50% off!"
"That's nothing," replied the mom in a bored voice. "The other day they were buy one, get one free."
It still makes my head hurt.