I wonder, what is the real average cost of running fediverse instance nostr:npub108pv4cg5ag52nq082kd5leu9ffrn2gdg6g4xdwatn73y36uzplmq9uyev6 ? Are there any 'purist' instance which running freely (covered by donation or owner's own fund) pure by instance owner?

What do you think about free relays in Nostr in long term?