Generally I find Black Friday a bit overhyped, the "bargains" are best checked against price history with (say) CamelCamelCamel before you buy.
Not Black Friday, but in the UK and maybe other countries, Amazon Warehouse is currently doing a 20% off sale, so 20% off the price when you get to checkout.
I've had a few good "As New" things off there in the past, worth having a look.
There's also a 50% off books sale on the UK Warehouse, loads of tech books, though I don't know how many decent ones are left.
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Specific Black Friday deals though: Quest Apps on sale:
https://www.oculus.com/experiences/quest/section/15301901340...