Nostr is nowhere near that scale.  Nostr has about 10,000 DAU.  If 1% of them paid $10 a month.  That would be $1000 a month to cover all the relays, all the developers, all the apps and so on.

The cost of managing a paid service is many times more than the cost of the storage or the compute.

So nostr would have to grow at least 10x for that to reach break even.  Which at current run rate, would not be for a few years.