Atlassian has such a pricing scheme. Pay x amount per year for the cloud version, x-x/10 for the self hosted license and half that amount yearly for updates and continued support. Of course you can still use the license without updates and support. The <10 user license is almost always $10 so that the entry bar is set low, other licenses are much more expensive (>100x) with price going down with numbers until you hit the datacenter versions which are priced differently. I think it's very flexible and covers just about every use case.