On the Fireside Fedi interview with Jerry ( the admin of Infosec.Exchange Mastodon instance ) a scary truth was suddenly revealed ( on 34:11 ): Just to keep the instance up and running he needs to spend up to $5000 a month, pretty much out of his pocket. Donations to the instance barely cover any of that. And if he will ask people to pay to use it, they will, rightfully so, switch to a different instance.
I suppose this community is as good as any. But it’s difficult to talk in general about this as each fediverse app has different performance needs/characteristics, so I’m not sure if you can extrapolate anything in general. But perhaps?