Similar, but on a rather different scale, I was reading Jay Leno's page in an edition of Octane magazine. He relates an incident of an elderly widow getting in touch to see if he would be interested in buying her late husband's old Ferrari. She knew that $400k was a lot of money but her husband had told her it was worth at least that. Jay phoned her and ascertained that it was a 275GTB, told her that yes he would give her the $400k, but the car was actually worth at least $3 million!. Put her in touch with an auctioneer he knew and told her that if it made more than $3 million he'd expect her to make him some chocolate chip cookies, which she though was fair!.

The car made $3.75 million!