Paul Copplestone, co-founder of Supabase, writing in a blog post: On February 1st 2024, AWS will start charging for IPv4 addresses. This will cost $0.005 per hour -- around $4 month.
Finally! Hetzner started charging IPv4 addresses (or rather, allowing a discout if you do without: the total price is the same it was vefore) since a few years and I guess that's working fine for them.