@hembrow While at uni, I used to work at a self-help repair shop for students.
A lot of people came in with bikes like these. Most of the time, we could send them home with everything fixed, for under 10€ in parts.
This being Germany, a lot of them had Torpedo 3-speed hubs. Those were mostly indestructible; and if something did break, they were reasonably easy to take apart and fix.