> but there is an opportunity cost

Is there?

Yes. They could sell the IP address to someone else.

But... they're selling it to you.

It's more valuable to be in use than to sell it to you. They are very limited on ipv4 space, so the charge is really a penalty for keeping that resource from another customer.

IPv4 allocation limits are still mostly a scare tactic to get people onto v6. I know dozens of people from my webhosting days with /12 and /16 allotments doing nothing that they pay peanuts for. This isn't a unique scenario.

That's not relevant, if I have 10 cars and you need a car ... then all that matters to you is that you need a car, not that I have 10 cars sitting there doing nothing. People sitting on IPv4 addresses don't care but new entrants cannot get new IPv4 addresses since they're all allocated.

> This isn't a unique scenario.

And this is exactly why we're running out of publically available IPv4 addresses.

I think the point is that there's a reason they charge you for it instead of letting you hold onto it for free.

They aren’t, unless you have an instance attached to it.

yes.