Jonah Lehrer curses expensive Internet charges at hotels and explains how our brains justify them:
In the end, expensive hotels are able to charge insane amounts of money for Cheerios and wifi because these exorbitant charges get posted to the mental account of the hotel bill, which will be hundreds of dollars anyways. As a result, the charges don’t seem quite so crazy. (This also helps explain why cheap hotels are so much more likely to offer free internet and breakfast buffets. Sometimes, we get more when we pay less.)