Recently I got for free an old Zeiss Super Ikonta 531/2, it's a medium format foldable camera from 1936. It was in decent shape but the lens was very foggy. Fungi can grow on lenses but I think it was just general dirt. Opening it was a bit tricky (I had to get watching-making tools, because the screws are very tiny) but I managed to clean the lenses quite well. I shot a first roll but the focus was off, so I had to make sure the front lens element was at the right distance, using some semi-transparent tape on the back of the camera to see the image.
Then I shot a second roll and developed it myself, which was also a first (it's not super hard though), I had no idea if the images would come out good, or even at all (wasn't even sure I loaded the developing tank correctly). Seeing the images come out of the tank for the first time is quite magical, and they came out great (some of them at least...) :
Even with my crappy development & scanning I can get high-res images that compete with my expensive digital camera. The lens (Tessar 105mm, f3.8) is quite sharp wide open (statue shot) and I even took a long exposure shot at night using a release cable. The process is very slow and focusing is hard, but it's quite fun and rewarding. These kind of cameras are very cheap but the rest (film, accessories, development, repairs, ...) not so much.