Well said. I’m often nonplussed at these calculations of some fairly high hourly rate that we seemingly all should be able to command at will at anytime in unlimited supply. Well, I can’t.
If you would otherwise be doing anything with positive expected utility in that time, the opportunity cost is >$0.
The fact that the analysis can be carried out in monetary units (because we don't have a good direct measure of utility) doesn't mean that receiving money itself is the only source of utility that needs to be considered.
Most of the time my time spend operating my A1 Mini is... maybe 2-3 minutes per plate? Drag and drop into Bambu Studio, run the slicer, send the job to the printer, come back in 4 hours and grab my prints. I might need to break off the supports and clean them up - but with an injection molded kit I'd be snipping the sprues, cleaning up mold lines with a knife and gluing the models together anyway.
The commericial overhead rate for an SLA printer is about $5 a plate - the washing and curing steps can be largely automated, or even if they are done manually, it's not that much work.
People who 3D print as a hobby often derive enjoyment from time spent on the printing process. It’s another layer of hobby on top of the hobbies you’re printing
Yeah a lot of my friends legitimately enjoy the art of making or modifying models in Blender, and the science of testing different print profiles, materials and processes.
