[quote name='BudzMcGee']As some have pointed out, many states do have laws that require that stores have to honor advertised prices on a shelf. They have every right to take that price down immediately after so that they don't have to honor it any further, but without something stating that the price is an error (ever seen a notice on the door about a "misprint" in a sale ad? Many states actually require they do that), many states do have that legal requirement. Again, many but not all.
Before someone brings up an online example, online stores are legally allowed to cancel mis-priced items ordered (but they couldn't charge you the "correct" price and send it to you anyway). Many states have this law because less reputable stores might intentionally leave some items marked at a lower price knowing that many shoppers wouldn't notice (let's be honest, if you were grocery shopping and a few items were $0.50 more than marked you probably wouldn't notice).
Stores could get into some pretty serious trouble for not honoring these laws if they are in a state with said laws, but you'll have to jump through more than a few hoops to make that happen. Most stores are going to just honor it that one time, then take down the mis-priced sticker. For a big enough price error a manager is more likely to take the chance you'll just not follow up enough and deny it.
Of course there is also the aspects not mentioned here like: the card is free, activating it cost money (really a pretty sleazy pricing gimmick, but more gray legally), or if the card has a price listed on it that would qualify as having been properly priced.[/QUOTE]
The only pricing laws I know of are for bait and switch tactics. These ONLY cover advertised prices, Meaning circulated outside of the store.
The difference being that an advertised price may entice a person to come in and thus the bait portion.
If the price is only a sticker instore that isn't advertised then you are already in store and there is no "bait" to get you in, since well.... You're already there. The only way that these shelf sticker prices are then spread is by word of mouth. And as far as I know a company can't be held by a consumer driven word of mouth advertising.
If you can cite other laws that go even further and actually mention sticker prices on shelving then I would be glad to learn about them and rescind my comments.