I hope this isn't off topic, it seems specifically economic to me even though it probably intersects with other fields of study.
Black Friday is seen as an iconic hallmark of consumerism, and Buy Nothing Day is a reaction to it that's been around since the 90s. It's a protest against both Black Friday as well as consumerism in general, and a temporary boycott to draw attention to the issues. I get that the consumerist mindset being protested during this time is buying a bunch of unnecessary stuff just because it's on sale versus getting that one thing you couldn't afford but now you can. And on a wider scale, I get BND is protesting buying a bunch of unnecessary stuff period (consumerism).
But on a functional economic level, in relation to things people would be buying anyway, doesn't boycotting Black Friday just amount to paying full price (or finding other sales) at some other time of the year versus taking advantage of these sales? And thus wouldn't that be something that people of lower economic status would be excluded from participating in, as they wouldn't necessarily have the luxury of choosing to pay more just to make a statement?