This very rarely happens in MA, because when it does the store has to give you the item for $10 off, including if that makes it free. And they have to post a sign at the register explaining the law, which means when you're invoking it all you need to do is point at the sign.
https://www.mass.gov/info-details/consumer-pricing-accuracy-...
I wanted to purchase a laptop at the advertised price. The sales person told me i was in luck, because all their laptops came preinstalled with Microsoft Office for a little extra money. I told him politely i did not want to buy Microsoft Office, even for such little extra money. I just wanted the laptop.
Semi-flabbergasted he told me this was not possible, because all the laptops had Office pre-installed. I told him i did not care and wanted to buy the laptop for the adverstised price.
After 15 minutes of discussion, some manager came frustrated what the problem was. I pointed to the price tag and told him i wanted to buy the laptop for that price exactly and if that was possible. It was, but it would require uninstalling Office, which took them another 15 minutes.
So i waited for another 15 minutes so they could remove Office. Back at home i powered on the laptop, popped in a usb disk and removed every partition that its harddisk ever had and started a nice fresh install without any bloatware.
There are of course exceptions; I can recall not long ago for example buying a pound of Himalayan sea salt for a dollar. That was a solid deal, and I haven’t seen it since.
But generally speaking, if you want to save money, don’t go to Dollar Tree.