Yeah I now what you mean. Sometimes we need stuff in a hurry and If you are not educated in 3D modeling then printing something you need is not feasible. And It also depends how much your time is worth. If you like geeking out and spend hours learning 3D modeling, then I think the printer will be paying itself.

I bought 3d printer mainly to print some custom parts and realizing my ideas but I know nothing about 3D modeling. I still have to spend hours learning how to realize something from my brain to solid objects.