what would you call a “nip05”’s value?

Hmm. I would ask you to stop calling it that and instead call it a Nostr address. And since I started doing the first Nostr address service provider, I'd say it's pretty valuable. It's an easy to read format for your public key, an easy way to be identified and found on Nostr. People change them all of the time. Some people don't find them valuable because he don't care about their identity as much as others. Those that do find value in them. I'd say it's subjective.