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 I don't use an anesthetic, I can knock it down to $60.00, but it would be very painful"

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

"Okay," says the dentist. "I can save time if instead of using my normal surgical procedure, I simply rip the teeth out with a pair of pliers. I could get away with charging $20.00"

"Nope," moans the man, "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 $10.00"

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