I read once (sorry, don't remember where) that DR priced it that way because CP/M utterly dominated the 8 bit market and felt CPM/86 had the brand name and the technical superiority to charge a higher price.

The miscalculation is that IBM PC sales were mainly to first time users who had no history with CP/M, and (as I mentioned) the technical superiority of CPM/86 was not apparent.

The only "technical superiority" of CP/M that I can think of is having files associated with separate users, though I can't imagine anybody ever used this. The PIP command, copied from DEC OSes, was a lot more awkward than COPY in DOS.

But a significant problem with CP/M was that if you swapped a floppy disk in a drive the system wouldn't notice it and things could get really messed up, so you had to remember to always control-c after changing disks. DOS would check, which reduced performance but was much more user friendly.

DEC had COPY on their PDP-10 operating system at least as far back as 1975 when I started using it. DOS clearly had a lineage going back through CPM to DEC.

The CR-LF line endings also trace their way back to DEC.