Yeah, on those rare spec chips that are not on the retail market, Apple probably have to place custom order to the memory chip manufacturers for a low-yield production, which is definitely causing the unit pricing to be much higher than the mass produced memory chips. Economy of scale. (even if Apple is still a big customer, it's still a small order to make if no other computer makers use that spec of the chips)
>Apple probably have to place custom order to the memory chip manufacturers for a low-yield production
Except LPDDR3 is not a custom low yield part since they're present in phones, game consoles, SSDs, cameras, VR headsets, etc. They're as off the shelf as they get.
