The rest of the Fediverse should put together a GoFundMe to buy the domain, and stick up a page with links to donate drones to Ukrainian soldiers, and care packages to families of Uyghur muslims detained in concentration camps in China.
I wonder if the high bids will actually go through or if it's just trolling. Definitely weird to give such big amounts of money away for a joke outside the space where it's needed.
That's not how the Fediverse works. Instances are per domain, not per IP address. You can change IPs however often you want, as long as your domain points to the right server.
That doesn't matter to fediverse software. Any new instance on hexbear.net would have errors when trying to federate with other instances, and it probably wouldn't be able to do so at all. But even if it did manage it, what are you expecting to do to mitigate the errors that arise from other instances referencing users/threads/posts/comments/communities/modlogs that existed on the old instance, but do not exist on the new one?