Also, don't forget that one can buy a Samsung 960 Pro in a machine that comes with a cheaper SSD but uses a standard M.2 NVMe slot, and ditch the original SSD,

Also, don't forget that one can buy a Samsung 960 Pro in a machine that comes with a cheaper SSD but uses a standard M.2 NVMe slot, and ditch the original SSD, for cheaper than any of Apple's capacity upgrades.