One day, a man 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 man says. "Isn't there a cheaper way?"

"Well," the dentist says, "if you don't use an anesthetic, I can knock the price down to $60."

"That's still too expensive," the man says.

"Okay," says the dentist. "If I save on anesthesia and simply rip the teeth out with a pair of pliers, I can knock the price down to $20."

"Nope," moans the man, "it's still too much."

"Well," says the dentist, scratching his head, "if I let one of my students do it, I suppose I can knock the price down to $10."

"Marvelous," says the man, "book my wife for next Tuesday!"