Some places try to argue something like that, but if you push back a little they cave. The law estipulates a fine ranging from 74 to 1 000 000 USD for visible products in shelves or display without a visible price tag. And since its a fine, the government is eager to get his piece of the pie.

(Edit for misspelling)

This is crazy, not displaying the price of an item in a shelf or display is against consumer laws where I live. And if the price on display is not updated the store is required to sell by the price on display.