I know it's a poor substitute for legal research, but Google is basically telling me that it's a myth that sellers have to sell their products at the advertised price. That comes as a surprise to me and I'm sure most of the public. It's widely believed, apparently mistakenly believed, that a seller may not attract customers with a price that brings them in the door only to tell them as they're checking out that they will have to pay something more. This happened to me at Staples a year or so ago, and the manager said, well, it's not the right price but we'll give it to you since it was our mistake. I was buying copier paper, so it didn't amount to much. My friend's wife was looking for a new fridge and saw a price she knew had to be a mistake. She took the ad down to the store and insisted they sell it to her for that price. And they did.