Depends what you mean by that?

I could port forward to a server in my home and host for free, but that adds complexity and raises security issues, also reliability is a factor.

I could host on any public service, you can do that in a small way for free, but high usage requires fiat.

I could setup my own server in the cloud, but that requires fiat.

Mostly, if I'm going to pay for a public service, I'd rather do this on a NOSTR focused server and support the developer.