Regardless of dynamic pricing, I have learned to check the price of more expensive items by scanning the barcode with my Wal-Mart app. Very often I have found discrepancies between the shelf price and the scanned price. In general it has gone both ways - scanned price cheaper or more expensive.

Inaccurate pricing is a management problem. All it takes is a dedicated team to go through one section at a time and update shelf prices.

Another management issue is inventory control. I have gone to a store for an item, where online i will be told 25 are in stock, then get to the store, an employee verifies the quantity on a handheld, and then no one can find the item, either on the shelf or "in the back". This is especially an issue with clearance items in my experience.