Yes, but those are per category not per consumer, which is a meaningful difference here and one you can't just ignore. Imagine a price label with a small camera that sends your facial image to a classifier of moods. Hungry? Pay 15% more. As you remove the item from the shelf, the tag reads the GUID from the item and records the price in the stores DB. Then, when you checkout, you pay that price. Someone else comes in get one price, balks, walks away. Comes back and ponders a while. They only get 5% above the base. Someone runs up and grabs and item without really looking at the tag, they pay 50% more. Now imagine that it gets it wrong half the time.