Alright, that’s totally understandable. As a service provider grows, it needs to obtain more and more IP blocks. Are there ongoing costs to owning a block of IPv4 addresses, or is it just a one-time purchase fee?
There technically is an ongoing fee to keep your membership (at least with ARIN there is) but it's so small to be meaningless.
Some providers rent their ipv4 blocks rather than purchase them, because the smallest volume you can buy in is 1024 addresses which is pretty expensive, especially for newcomers. In that case there would be an ongoing cost.
You can get /24's (256 addresses), you don't need to get a /22. Anything with a longer prefix is not generally allocated by regional internet registries, and won't usually be accepted over BGP.
Some providers rent their ipv4 blocks rather than purchase them, because the smallest volume you can buy in is 1024 addresses which is pretty expensive, especially for newcomers. In that case there would be an ongoing cost.