As of 2024, the depletion of fresh IPv4 address blocks has led to a surge in prices for IPv4 addressing, with entities selling blocks for over $10,000 per /24. While some have benefited from this price increase, others have struggled, resorting to Carrier Grade NAT due to unsustainable costs. Despite this, there is a significant amount of Class E space in IPv4 that remains unutilized, with potential for local network use. Some networks, like AWS, have already begun utilizing Class E space. However, global acceptance of Class E space faces significant challenges, making migration to IPv6 a more viable long-term solution.
https://blog.benjojo.co.uk/post/class-e-addresses-in-the-real-world