Machining is a good skill to have. The ability to shape objects to tight tolerances comes in handy from time to time.
A buddy went all in a bought a huge milling machine, but I'd prefer the table top version to start.
You can start really cheap with just basic hand tools, there are lots of bench size machine tools, like mills and lathes, that come onto the market as their owners age out.
Know that if you do get a mill, lathe, CNC, etc... fixtures, jigs and cutting tools will cost at least as much as the tool itself. All the things like vices, t-slot hold down kits, various milling and lathe bits add up fast.