While price of ipv4 addresses are increasing, the world has slowly been adopting ipv6. From the graph above, I'd say we cross over 50% in about 2-3 years time. At some point the "dash" to adopt ipv6 starts, and brave folks will drop support for ipv4. Then it'll probably evaporate between 2030-2035.
https://www.google.com/intl/en/ipv6/statistics.html
While price of ipv4 addresses are increasing, the world has slowly been adopting ipv6. From the graph above, I'd say we cross over 50% in about 2-3 years time. At some point the "dash" to adopt ipv6 starts, and brave folks will drop support for ipv4. Then it'll probably evaporate between 2030-2035.