We don’t know the unit cost of those parts, but we know from past statements they are a very small proportion of what Intel is charging OEMs for their processors.
Given that the perception has always been that MacBooks are the best built laptops available, but priced at a substantial premium, it’s been fine for a Dell or HP to coast by on lower prices and thinner margins (as long as Apple wanted 30% or so in profit on each unit sold it was easy to compete on price and still make a living).
With the M1, Apple now has the option of competing directly on price while preserving their margin, with a substantially faster machine, that still has the other premium elements (e.g. the aluminium body, the massive trackpad).
I don’t know how any one of their competitors can compete with a similarly-priced device that is faster, better built, and commands much higher residual value down the road.
Maybe I’m being naive but I’d be very worried right now if I were Dell/Lenovo/HP, especially given that Intel doesn’t have a working 5nm process.
It’s even worse for companies like Hynix, given the performance gains from the on-package memory architecture in the M1. AMD are going to have to go down that route now to compete, and that doesn’t leave much room for direct-to-consumer DRAM vendors (although given the questionable histories in that market it may not be the worst thing for the consumer).