That's just wrong. You could (or still can?) buy mac os installation dvds in an apple shop for 30 bucks (iirc my sister bought one a few years ago) also the "upgrade" to sierra is free without any limitation on how many machines you can legally install it on so you can create an installation medium (you can install it in qemu or probably even use coreboot with a modified tianocore to actually install it).
Oh and you can download the source for the kernel (I'm not sure which versiin this really mirrors and I'm not a mac guy so I don't care) here https://opensource.apple.com/
Just because you can't easily buy a copy of it at best buy and install it without some hacking on any random computer doesn't mean that you can take the price of the cheapest mac _hardware_ say that's the price of the os and call it a day.
Also your comment did completly miss the point of the parent comment.
Also your comment did completly miss the point of the parent comment.