One day a lady walks into a dentist's office and asks how much it will cost to extract wisdom teeth.
"Eighty dollars," the dentist says.
"That's a ridiculous amount," the lady says. "Isn't there a cheaper way?" she asks.
"Well," the dentist says, "if you don't use an anaesthetic, I can knock it down to 20."
"Nope," moans the lady, "it's still too much."
"Hmm," says the dentist, scratching his head. "If I let one of my students do it for the experience, I suppose I could charge you just 10 dollars."
"Marvelous," says the lady, "book my husband for next Tuesday!".