Here is the link to my github repository.
It has:
Bill of Materials
Gerber Files for the PCB - these will work for JLCPCB I don't know about any other manufacturers
STL for the case
Sketch for the programming



https://github.com/trilerian/Rotor-Master


This project would cost somebody appx $165 after taxes and shipping, plus you would need to print the case. But that price is if you need to buy an Arduino Uno, breadboard, and stuff for that.
You will still need a digital multi meter. You would have some extra parts as some of the items are bought in multiples. If you price everything out per part and total it after tax and shipping it is about $35 per unit.