People literally are priced out of macs. Nothing you say changes that fact.
> About the final point—are Macs really "high cost"?
There are zero low cost macs, while other low cost computers are abundant.
> If a Mac is $2100 instead of $700, that's only a few hundred dollars more per year, or $20-30 a month.
Your concept of what “average people” can afford is very convenient for your argument because you made it up. To most people a product that is $1400 more expensive is considered much, much more expensive. The fact that you have to invent a payment plan to support your argument says a lot.
I like macs, they are nice. But they are high priced and expensive. They can be both worth the extra money while also being too high priced for a huge number of average people.