Just to clarify a legal point here - as jaydisc and others have already touched upon - Target has two legal options here:

1. Sell the toy for the advertised price of $23, or...
2. Withdraw the items from sale, remove all the Bumblebee/Starscream Value Packs off the shelves, then put up a correction notice and then restock the shelves - as evidently some Targets have already done. After this has been done, then they can sell the toys for $79 each.

What Target cannot do is sell the toy for $79 prior to putting up a notice.