i've always price matched black friday ads at
walmart...for years! As long as it's the exact same item and in a printed ad that you have with you they've always honored the lowest price on black friday. And they are also doing the price matches from nov 1st - dec 24th for price adjustments as well if you find a printed ad. All you have to do is take the ad in and they will adjust the price. This also includes anything you've purchased at walmart.com but want to match to a printed ad.
Now, they won't give you the black friday price on something you've already bought or buy after bf.
The last 3 years for sure i know i've done a one stop shop for everything at walmart that i wanted ad matched from other stores and then did the rest of my shopping at the other stores for anything that isn't sold at walmart.
http://www.walmart.com/cp/christmas-ad-match/1159720?povid=p1171-c1110.2784+1715.2777-l0
if you read under the faq section it states right in there that they price match on bf.
"we will match competitors' advertised prices for identical items in stores only on thanksgiving/black friday during times the competitor's ad is valid."