Since people seem to keep insisting that the price of something should essentially be the sum of the costs to create it, let's say Apple priced their memory upgrades at their cost. So adding going from 8GB to 32GB RAM would wind up meaning, say $50. Going from 256GB to 1TB would cost another $50 or so. Give or take, no exact numbers, but the point everyone wants to make here is that it would be much, much less than Apple currently charges.
Do you think Apple would release a series of products with only $100 between them? Would that be cost effective for the company or of any use to the consumer? Or if you see this as evidence that the low end products aren't worth producing at all, would they decide to only sell one model? What price would they likely sell it at?