One rare exception is the $4.99 rotisserie chicken at Costco. It’s been the same price for as long as I’ve shopped there and they proudly take a loss on the sale of each chicken so that you make the trip there. It’s even cheaper than their uncooked frozen chicken.
Issue with Costco is you need to pay for a membership and the fee is only worth it if you shop enough at Costco
People barely scraping by probably don’t buy enough to justify the fee, and also probably don’t have enough money to buy items in bulk Costco warehouse style for months/years of usage