> the Pi CM4 may as well be vaporware - they're basically impossible to find anywhere even in single-digit quantities
That's near as damnit true for _all_ Raspberry Pi products right now. You can pretty much only buy any of them in single unit quantities, and it's like buying concert tickets, you need to keep your eyes open to find out exactly when someone has some for sale, and you need to jump on them before they sell out.
I managed to snag a Pi Zero 2 W a week or so back, had to get it shipped from Spain to Sydney which cost more than the Pi. I was limited to a single one at checkout.