Relay operators WILL appear out of nowhere. People will probably say I did :-) I'd say I've been around since I write the first uk.finance FAQ on Usenet :-)

There will be scams, because a PAY ONCE model is not sustainable, but while it's essentially the only game in town, and people have no idea what fair charges are, I predict the following :-

Mainstream Media notices Nostr. Scammer buys ads next to those articles, uses all the usual tricks re click-ad, pitches a top end price via a fiat front end. "Just 10 bucks, GOLD LEVEL MEMBER, Free Client Software". Pulls in money, vanishes. As with all scammers, they prey on the new. People who don't know how things work.

The best way to mitigate this is to move to a per month or even per post (if spammers start to pay to relay) model for pay models. Roll out others as you like too. But an ecology of "once only" is where scammers will come and they might thrive.

The next thing that will make it harder for scammers is relay differentiation. I run a relay. I'd like to say "I run a relay out of the UK, following UK law, so great for Brits and other english speakers". Right now, I can't. (But I did see the post that suggests soon, I'll be able to).