Running costs of 3D printing
I have a Prusa I3M3+MMU2, which I have had for a year.

During the first year, the display failed under warranty and replaced for free.  The power supply also failed, and although Prusa replaced it, I was in a hurry and bought another supply to use as a backup for about \$60.00.

I have used two rolls of paper towels, a bottle of acetone, and a quart of isopropanol, for maybe \$5.00.

I have bought a spare thermister for about \$10.00, but haven't installed it yet.

I bought a couple of new nozzles for specialized materials for \$35.00, but the nozzle I got with the machine isn't worn.

I bought the textured build plate (when it was finally available) for about $30.00.

So, my running cost, exclusive of electricity, is about \$140.00, including buying accessories which haven't been consumed.

I have also bought way too much filament, which you aren't counting.  Filament cost has dwarfed my other expenses.