Is there a 5$-30$ IaaS that supports some rolling-release distro?
Linode is one of these (see linode.com). Linode offers 5$ ArchLinux and yesterday I talked with their staff and two staff members confirmed to me that they can't find any plans to stop supporting it in the future, so that's good.

According to ArchLinux wiki here, Arch Linux is a full rolling release OS which is basically "true rolling release OS":


  Linux Mint Debian Edition (LMDE) is based on Debian Stable and only
  receives updates in Mint packages and security updates. Arch is
  instead a full rolling-release distribution.


I understand that to be the highest one can go in rolling upgrades and of release as well.