A wealthy man was very ill. "there is only one thing that can save your life," his doctor told him. "a brain transplant. but it's very expensive."
"money is no object," the man said." can you get a brain?"
"there three available.the first is from a professor. it'll cost you $1,000."
"that's not much for a brain. how about the second?"
"the second is from a scientist. but it'll cost you $100,000."
"don't worry. I can pay. what about the third?"
"the third is from a politicion. but that will cost you half a million."
"why so expensive? what's so special about it?"
"it's not used."