"When contemplating the purchase of a $25 pen, the majority of subjects would drive to another store 15 minutes away to save $7. When contemplating the purchase of a $455 suit, the majority of subjects would not drive to another store 15 minutes away to save $7. The amount saved and time involved are the same, but people make very different choices. Watch out for relative thinking; it comes naturally to all of us. "
http://www.codinghorror.com/blog/archiv