Self-hosted website looks too expensive, unless you paid someone to make it. I host FoundryVTT for my group, and the only paid thing was Foundry itself and my internet-connected PC I already had.

Public IP? No need to pay extra. DuckDNS when you're not behind CG-NAT or Cloudflare ZeroTrust reverse proxy when you do or have no access to your router.
Domain? I've seen at least two sites that provide them for free - digitalplat and the other I can't remember.