The UK certainly has some weird laws, but that sounds...of dubious validity. Like roughly the equivalent of "not for individual resale"; a contractual matter between the supplier and the merchant, not something that could even theoretically be enforced on any buyer.

I doubt strongly that this would have any effect either, for the same reason. My legal knowledge is a little old fashioned and sporadic, but the classic authority on this used to be 'Olley v Marlborough Court Hotel'. Worth a read, if only for the way Denning used to write his judgements.