Ah, in part, it's a sign of the times...
Prices on most things will rise eventually, but I'm hearing that groceries will probably see the biggest spike on pricing. It would appear that the prices you saw were just the store owners putting out their "feelers" to check what people are willing to pay. Obviously, they over-shot the margin just a tad if they still had regular pricing, didn't get marked down for "quick sale", and then of all things, let them go beyond the labeled sale date. Poor management of stock, for sure.
I found a store like that about 18 years ago where the cold-cuts, hams, cheese, hot dogs and pretty much any and every processed perishable food item was outdated, and obviously had become spoiled as the packages of most of the meats were bulging to the point of nearly bursting. I carefully picked up a boneless ham just out of curiousity, and the package was so firm that it felt like grabbing onto a basketball. The sale date was more than three months expired, so it wasn't like they had a power outage for a day, and then just got back on line and didn't have refrigeration temp monitoring to know if they lost anything or not.
I did an about face and made a bee-line for the door, never to return. Funny thing was that they never got shut-down for that, or any other health issues, to my knowledge. I lived about 50 miles away for over 5-1/2 years and I never heard a word about it. I think management had more than a couple inspectors in their hip pocket, because I can't imagine an auditor missing 75-80% of their perishables being, well, perished.
That store was/is part of one of the larger national chain grocery stores, btw.