You'll get much more out of a mill or lathe in this hobby than a 3D printer.

Again, I use mine almost daily, but never for finished products. Where it shines is it's ability to be precise and consistent. I had to make a master for a 1/8 Japanese Diving Helmet. The shell, broken in half, the window grating, the lip and socket for the mask plate, it's outstanding. It would take me a long time to scratch build that with raw materials and in the case of the grating, it'll be very hard to get a perfect pattern. Printer? No problem. But for shell, while it's precise, the finish needs an extraordinary amount of attention and finishing and that's printed at 50 microns.

I've printed out end caps and ballast tanks for RC subs. It works like a charm, placing O ring grooves, etc. Before the printer, I did it with Styrene blanks and a lathe. Very time consuming. The printer, 20 minutes in design and print. If I need 50 of them, I make 50, hands off. But again, it's not a finished piece, but a functional piece. The lathed blank will bet much prettier.