Lisa needs brain surgery and figures it’s easier to buy a new brain.
She asks the doctor what he has on sale.
“Well you’re in luck I have two in stock, a man’s brain for $10000, and a woman’s for $1000. “
Surprised, she asks why the price difference?
“Generally women’s brains run cheaper because they come to us used!”
This joke is included in the Black Book of Jokes. You can order it from here.