It's not obvious to me that Apple does make a significant amount of money by selling upgrades. Almost everyone buys the base model. The other models are probably little more than a logistical pain in the butt from Apple's perspective. Apple has to offer more powerful systems to be credible as a platform, but I wouldn't be surprised if the apparently exorbitant price of the upgrades reflects the overall costs associated with complicating the production and distribution lines.

Yes, but you understood what I meant since you could assert that it’s not what it means.