I think they are now required to have a price sticker on EACH INDIVIDUAL ITEM, not just on the shelf, but I may be wrong.
I was talking to someone in a MA supermarket today and they said it is every item. However, multiple exceptions are made for frozen items, eggs and cards amongst others.
Apparently, the number of registers in a store also has something to due with the requirements, which can result in thousands of dollars of fines for unlabeled items.
Its petty time consuming to price every single can, bag, and box in a store.
In the factory we tied putting traceability tags on every single part till we leaned how time consuming it really was. We knocked it back to 5 out of every 50 parts with a tag on every individual box of parts.
This would make scanners irrelevant. You would have to change prices on existing items on the shelves. Also, it would drive up labor costs by forcing stores to do totally unnecessary work. Those costs get passed on to consumers. Massachusetts seems to be filled with highly educated idiots.