Ah, Black Friday. The biggest (and most malevolent) shopping day of the year. A day of good deals, hateful people, and... other stuff. If you're willing to brave the all that for a new phone, Sam's Club has you covered this year, with the Galaxy S III going for less than a buck with a new two-year agreement.
From what we gathered by calling a few different Sam's stores, this is good for all four carriers (so long as your local Sam's has them all). The ad doesn't specify, but it would just be silly to sell them for this cheap on one or two carriers and not the others.