Had a brief chance to look and here are 3 interesting nostr pay-to-relay servers that I have subscribed to:

wss://nostr.wine - paid 8,888 sats, nostream behind Cloudflare managed by #[0] . Nostr dev doing super cool stuff with a private relay, like his "filters" feature

wss://relay.orangepill.dev - paid 4.5k sats, US nostream managed by #[1] Public SRE means this admin is deadly serious about their uptime!

wss://nostr.ownscale.org - paid 4k sats, EU nostream managed by #[2] on a dedicated server at ownscale. Sounds familiar.