In the UK, it's common for supermarkets to have loyalty cards (e.g. Tesco Clubcard) and then they display prices along with the price for using a loyalty card.

In the UK, it's common for supermarkets to have loyalty cards (e.g. Tesco Clubcard) and then they display prices along with the price for using a loyalty card. Then, they just apply the discount (which varies according to the product) when you swipe your card before paying.