I make a difference between what FB customers pay for promises of brain time, and what the service FB provides actually is worth for _me_ (people are no customers of FB). $40/month/user might be what FB get from their customers. It does not mean that it is the value it is actually providing to its own end users (excluding ad afficionados if that exists).

There is also a difference with what it actually costs to provide the useful part of the service. Mastodon is open source, yes it requires hardware (virtual or actual) and operation, none of which is free, but the cost of these certainly doesn't match the cost of running+developing game changing (advertisment/recommendation) ML models and ultra high scale infrastructure. Running a mastodon server for a thousand users with acceptable availability, and no fancy ML or R&D, I think should be doable for $5.000 a month, yes.

But that doesn’t mean an equivalent service cannot survive on just a dollar a month.

I think this is why youtube without ads is sooo expensive.