The problem with your observations is the timing. Smaller supermarkets like that Supremo can't keep up with the constant increases from suppliers which under high inflation has been unusual. The same applies also to other supermarkets but some of them are much larger; generally when you point out something to Supremo they check and give you the lower price and add that to their huge list of updates to be done.

Stop and Shop and ShopRite, two much larger companies, have many advertised specials that do not ring up properly because they can't make their advertised coupons work properly on computers and always keep asking you to download their apps instead that run on tiny cellphones screens. Why can't large, some billion dollar ones, companies get simple programming correct?

Supremo is not that bad, I am fairly certain that usually give you the lower marked price unless price is too old (they can't afford to take large losses and they serve several communities). I suggest you be kind to them and forgive their problems, its not worth walking to Hoboken where prices are much higher than Supremo's.