My mom explained that it was a way of saving money, and that not everyone has enough money to buy everything that they want. She subsequently found something for Pumpkin to watch on PBS, which made Pumpkin happy enough.
You'd think that this would have been the end of it, but later that night, I found Pumpkin in her room, ransacking her piggy bank. "What are you doing?", I asked.
"Getting some money so we can buy Grandma some cartoons!"
The other day, I was grocery shopping with Pumpkin. I remarked on apple sauce being on sale, to which Pumpkin asked, "What does 'on sale' mean?"
"It means that it's cheaper than usual.", I explained.
"Oh," Pumpkin replied. "Grandma likes cheap!"