Usecase: Students tutor other students, and for auditing and error-detection purposes, both the tutor and the tutee must log times and submit them. This is about 80-120 students total, depending on the year.
A separate third party--possibly a parent of the students--would then approve. So that's another 50-60 users.
A cost of low-price--it's donation run--and long-term maintainability is what I'm looking for here, which probably isn't likely; I'd love if I didn't have to administer anything at all.
Second best is not requiring deep tech and IT knowledge to maintain long-term, because I'd rather hand this off and not code at all. So some minimal custom-coding to fill-in the gaps is okay.
Finally: Because this is student-lead and run, cost is a factor; so the per user costs aren't feasible. Right now, I can't see a way around at least custom hosting on something like Digital Ocean.