A survey done showed that something like 60% of the stuff on sale on Black Friday has been, or will be, on sale at cheaper prices at some other time during the year. Especially "Tech" goods.
I genuinely just ignore the black friday stuff, get my discount hunting going after christmas or early january (quite often on ebay) and to backwoodsman's point I always always check the price and don't just believe the "sale" label. good luck with your sale hunting