EA's Origin has currently listed Battlefield 3 as $30, 50% off, and says the deal will last for only today (Black Friday). The deal is allegedly available only to North American users of Origin, so if you're interested in BF3 and haven't picked it up yet, now might be your shot to do so.
If you haven't already seen our Black Friday Survival Guide by FJ, check it out here to capitalize on those deals!
You can view the deal here:
If you're not sure whether or not you can run the game to your liking, we've learned the following:
Generally speaking, the 560 Ti can run the game on 'High' settings; the 570 can max the game out; the 6870 can run the game on 'medium-high' settings, the 6850 should run it around medium-high as well, and the 550 Ti will run it on medium with some gizmos disabled. This will vary based on your other system specs, but as a general rule of thumb, it should help you figure out if you'd be happy with the settings.
I should note that the game looks fantastic no matter what, so don't let the graphics settings discourage you. Remember that this is all about relative depravity -- BF3 has high specs because it looks good naturally, so it has higher standards.
Enjoy the rest of your shopping weekend!