The two places that jump out at me as possibilities would be restaurant supply places (for example, Gordon Food Service has storefronts in my area though I don't believe they actually sell to the general public) or "ethnic" markets - often small-chain grocers often listed as "produce" or "carniceria" though they are often full service groceries.
Gordon Food Service storefronts all sell to the general public as of a recent rebranding. They're actually very accessible - though like Costco or Sams Club, more applicable to feeding a large group. Some prices are up at https://ads.gfsstore.com/.
In New Orleans, one sees these prices at local chain supermarkets (i.e., not Winn-Dixie or Whole Foods but Dorignac's or Canseco's) as well as what could be politely termed bodegas in the middle of urban food deserts with crime challenges (one local chain of which has the incredibly apt moniker Chicken Mart)
