There's also the issue of AWS actually running out and not being able to take on more customer, or at least larger customers. It is solely for the benefit of AW

There's also the issue of AWS actually running out and not being able to take on more customer, or at least larger customers. It is solely for the benefit of AWS, not it's customers in any case. If it was about the customers NAT gateways would get reduced in price at the same time. That being said, I do know companies that have freed up 80% or more of their IPv4 allocation with no service impact. It was simply not an issue previously and AWS made it easier to just allocate more public IP addresses. They at least hit the right price to ensure that people care, but not making it unreasonable if you do need an IPv4 allocation.