Price tags are one thing. The region-wide ads for Kroger saying "milk is on sale for $1.99/gal this week with your Kroger Card" are another. A broadcast TV ad

Price tags are one thing. The region-wide ads for Kroger saying "milk is on sale for $1.99/gal this week with your Kroger Card" are another. A broadcast TV ad like that might be visible in 10 or more different sales tax areas. Having worked in retail, I have several anecdotes from customers getting annoyed over even the smallest pricing discrepancies. I had one shopper complain about being charged less than the price in the mailed circular on the theory that the chosen product was of lesser quality than the advertised product.