While I was in high school and college I worked at a few large chain retail stores. During that time I learned about this cool law in Michigan that is geared towards forcing retailers to maintain the accuracy of their prices. At the time I found it incredibly annoying as I'd have to put a price tag on every little foam paint brush in a bulk case of 1000 (yeap that was a couple wasted hours each day), however other parts of the law do quite a bit if you know about them. (Hang in there 'til the end you'll see how this is hobby related)
Essentially what the law says is if a scanner rings up a price and it doesn't match what is marked on the product, the seller has to pay you the difference + 10X the over charge with a minimum of $1 and maximum of $5. (if the clerk doesn't catch the error before you pay) I guess the idea is that for the inconvenience of having to come back to the store or wait at customer service you're entitled to compensation. It also works to punish the stores for not keeping their systems up to date, nothing is more annoying than picking up a product and not knowing the price, or getting to the register and have it ring up for more than you thought it would be.
I'm not sure if other states have a similar law or not, but if you live in Michigan be sure to bring it up anytime you get overcharged. When the law first came to pass in the 1990's most big chains had to train employees and it was a pleasant surprise when you went in for your refund. However as of late it seems many large chains like Home Depot, Dollar General and more are choosing to ignore the law and swindle consumers. (man, I sound like a crotchety old man...)
On more than one occasion I've been over charged asked for the bounty and been denied because the employee doesn't know what I'm talking about. In fact once at Home Depot my wife bought some blinds that were marked $50 (along with a bunch of other stuff), when she got home and looked at the bill they charged her $75. I took it back in asked for the refund an bounty and was denied both twice by different managers. It in fact took two phone calls to their corporate headquarters and a complaint with the attorney general to solve the issue.
More recently I ran into the same issue with some 1:43 scale cars I bought at the Dollar General. I've been stopping at random locations to see if they have any other body styles of those bBurago cars for my near future board. To my delight I found several styles and they were marked cheaper than the first ones I found. I snatched them up paid and went to my car happy. At least until I looked at the receipt and realized they overcharged me. I went into the store and let the clerk know the issue and asked for the refund and bounty. Of course she had no idea what I was talking about and called over her "manager" who also looked at me like an idiot. After explaining the law and showing it to her she still refused ... So now I'm calling corporate to get this fixed. I'm sure I sound like a jackass for making such a big deal about this but the law is the law and I feel that unless chains are forced to comply with the law we'll continue to get shitty service, miss marked product and pay more than we should because of scanner or human error.
If you live in Michigan know your rights as a consumer and demand that chains follow the law. If Meijer, Target and Walmart can do it they why aren't these other chains held to the same standard? If you've been denied the bounty on scanner inaccuracies file a complaint with the Michigan Attorney General.