That's already commonly acknowledged behavior separate from the degrowth strategy the article is publishing.

Although, there are many politicians pushing to prohibit retailers from offering customers a lower price, when they notice that customer is unwilling to pay full price.

I don't follow your argument. Why would those facts make PSAs effective at changing consumer shopping habits?

If my response sounded like a non-sequiter to you, well, yours sounded like one to me. The article is not about whether retailers pay attention to shopper's habits, nor does it have anything to do with high prices.

Instead, it is entirely about whether advertising campaigns encouraging people to buy and consume less (for environmental reasons, not economic protest) actually change the behavior of the people who hear them. It concludes that they do not. Do you still beg to differ?