My folks have an old vacuum cleaner that they keep in the basement so they don't have to haul one up and down the stairs all the time. The latch to hold the dirt bin on broke. The part couldn't be purchased anymore and the vacuum worked fine otherwise. It was a quick design and quick print since aesthetics didn't matter. I used cheap PLA filament that I had from another project so all in all it was well worth the effort and cost to keep the vacuum running and keep more plastic out of the landfill.
I printed two prototypes to get the design right at .3 layer height with 20% infill. Final part was printed at .12 layer height with 90% infill.