[pocksuppet]

You can still get a block on the grey market for (I believe) currently a 4-digit payment, which is not free, but it's quite accessible if you have any serious usage at all.

(It will be officially transferred to your name - there's nothing grey about the blocks themselves - the greyness is that RIRs officially forbid selling them, but they can't really do anything to stop it and they don't forbid buying.)

IPv6 blocks are still available from RIRs and you don't really have to care about anyone stuck in the 1980s if you don't want to.

Also each of the root servers is itself run by a different organization. If you had some clout, you could ask them to also host your alternate root server on the next IP address. Half of them are anycast blocks which means they likely have 253 addresses free as anycast blocks aren't really shareable.