In the world of hobby-level CNC cost and simplicity are usually the name of the game. Using inexpensive and easily found materials makes a big difference in the feasibility of a project.
There are probably almost as many DIY CNC designs as there are DIY CNCs. And there’s nothing wrong with that! We really liked [maxvfischer’s] documentation on GitHub for a machine he made ...
Solar panels can save money or increase energy independence. If you want further savings, you can DIY solar panels, which requires more research and effort but can result in a cheaper system overall.