Here's something I've noticed on these sales. A few months before the prices start to raise. Little by little. By the time black Friday comes around they may be 30 to 40 percent higher than normal before the slow increase. Then black Friday deals, only knock them down to the original , before increase price. Making it seem like a good deal, but in reality, you are paying the normal price where if you were to buy it earlier you would of gotten a better price.
The thing to do, is company's come out with new products later, the black Friday is to get rid of old stock. Wait til January , February, new stock comes out, older stock comes in at a lower than black Friday deals.