That also means that you should beware of "analyses" that ignore the costs of staying on v4 and not doing v6.
NAT, split DNS, VPNs, RFC1918 clashes and renumbering... this stuff isn't free, and most of it is totally unnecessary when you have enough address space.
While the above are real costs, beware of promises that IPv6 will remove, reduce or even lower the cost of doing NAT. As long as there is an IPv4 Internet, NAT will be an integral part of any IPv6 deployment.
It will do all of those things in the right circumstances though.
Dual-stacked eyeball ISPs see over 50% of their traffic go via native v6. If they're CGNATing then that corresponds to a substantial drop in the amount of traffic that needs to be CGNATed, and therefore also a corresponding drop in the cost of the hardware needed to do it.
NAT, split DNS, VPNs, RFC1918 clashes and renumbering... this stuff isn't free, and most of it is totally unnecessary when you have enough address space.