Black Friday is a good opportunity to buy items at a discounted price and people take advantage of this opportunity. But I wouldn't wait until Black Friday before I buy an important item like a hardware wallet. Just because I want to save little money, one might incidentally grant criminals access to your hard-earned money. There is a saying in my tribe that cheap things usually have hidden defects. Some of the discounts offered by some trading platforms are too good to be true that is why we need to be careful. However, thank you OP for reminding us that we need to be vigilant.
If the discount is too good to be true, then it must be from a fake seller, but if it's from the direct shopping centre, either their link to their official website or you see a discount of such, then I don't think there is any harm in trying to get such an offer when you have the opportunity.
Black Fridays are times when shopping centres use discounts to sell off old stuff that they still have in stock or probably use the means to attract more customers to their store.
Those who fall victim to the too-good-to be true offers are those who are already in search of means to purchase a particular product in less value compared to what they are being sold in the open market. They are the type of victim that the scammers are in search of.