That isn’t actually true. The price on the shelf is considered to be an invitation to treat. By taking the item to the checkout you are offering to buy it which they can reject. In practice they will sell it to you for the price on the shelf but this is not the law

Buffy

A lot of these comments are American so I thought I would provide a different point of view. In the UK it is a legal requirement for some broadcasters to have a certain percentage of signed programmes.

This is a webpage from a guy who voluntarily because stateless. https://identityunknown.org/3e7/Introduction_A_series_of_life_experiences_by_Glen_Lee_Roberts_before_and_after_he_became_Voluntarily_Stateless

Tim Eicke, the UK judge at the ECtHR. He gave a talk at my university and I briefly spoke to him afterwards