I recently bought a 3D printer kit and made some lens extensions for a microscope, it works well for small parts like that.
It needs some work still to make it print ABS, but the kit is fine for PLA.
Keep in mind that many items can be made faster and stronger with simple (hand) tools from raw stock, however the printer can make unusual parts which would be dificult to machine, and it can work unattended.
It requires a change of mindset from subtractive machining, which I still struggle with, but has other limitations instead (such as bridging and overhang angle).
Approach it as a hobby and do not expect it to pay off any time soon. My main motivation was actually wanting to learn 3D drawing.
(I hope nobody remembers my deprecatory remarks about 3D printing made many years ago on this very list. At the time the first repraps were just spitting out globs of molten hot-snot and I was basically saying "it will never fly". Turns out I was slightly wrong, like that IBM man...)
Actually it would be fairly easy to make a CNC that can 3D print and mill/drill PCBs...
ST