It's different in different states. In Maryland, once a complaint is filed with the relevant authority, the store has a certain number of days to correct pricing. Most retailers will give you the misprice if it's clearly their fault in not changing the tags, as a matter of policy.
The confusion around this law is quite frustrating, though. Quite a few customers think they're entitled to not just prices on tags that haven't been updated, but prices for what are clearly entirely different products.
Is it a certain number of days to fix all the mispriced items?
If not, there’s an obvious loophole here. Misprice intentionally, then stop purchasing the item from your distributor if you get called on it, rotating in some similar thing. Later, bring it back with a different sku, or mispriced at some other level.
This would work well for dollar stores, which are optimized to spread in / sustain food/retail deserts.
The store is often literally the only option in town. The wouldn’t even need to sell excess warehouse inventory at the advertised price, since they could just shift supply to another state (or county/store, depending on how poorly the law is worded).