I mean, for SUSE or RHEL you can just build your own image and BYOL. There's no need to use the standard images. Anyway, if your infrastructure is static enough that the per hour licensing costs don't make sense then why are you even using Azure/AWS/whatever instead of running inside your own DC?

Every time our IT Director talks about Azure I want to cringe, our infrastructure is relatively static and only grows - so it's straight up MORE expensive to put anything there (and this factors in power and cooling to the datacenter).