I was reading an interesting story today on how someone was at a retail store and was in the process of purchasing an electronic device that is normally valued at about $200+ dollars. When it came to the actual checkout, for some reason the price of the item scanned at about 10 cents during the first time through. Although it scanned at the normal price after, the store had to honor the initial 10 cent price.
To my knowledge, there is supposed to be a rule in place that does enforce that to protect the consumer. Makes you wonder if an example like the above is a little too extreme though.