The only things I purchase in a brick-and-mortar store are groceries. The markets I shop at have the live display, and I usually watch that closely as each item is scanned. The only mistakes I have seen have been with produce. It’s easy for the cashier to put the wrong code in. Sometimes it’s the organic code, when the produce is conventional. Or occasionally, it’s just wrong – like entering the code for an exotic pear rather than organic fuji apples.