The comment by Adi Santhanam[1] who is an AWS product manager for networking has indicated a Lightsail pricing increase for IPv4 later this year[2].

> Yes, Lightsail is revising instance bundle pricing to accommodate IPv4 and new pricing will be published later this year. We understand the importance of bundled and predictable pricing for Lightsail, so revised pricing will include the IPv4 conservation charge in a monthly bundle cost and not as a separate charge.

[1] https://www.linkedin.com/in/adityasanthanam/

[2] https://aws.amazon.com/blogs/aws/new-aws-public-ipv4-address...