Gerrit: While browsing in a record store I noticed that one copy of a recording I wanted had mistakenly been priced at a quarter of the list price. When I finally reached the cashier I was told that the price had been mismarked and I would have to pay the full list price. Since I had wasted an hour standing in line, the retailer was morally obligated to sell me the recording at the lower price. Saskia: I disagree. You knew that a mistake had been made, and you were simply trying to take advantage of that mistake.
 The principle that the price displayed on an item in a retail store morally constitutes an irrevocable offer to sell the item at that price would most help to justify Saskia's position.