Disclosure: I work for Pivotal, which competes with Mesosphere in this arena. Read with discretion. If shilling persists, consult your techcrunch.
With that out of the way: you should try Kubo.
Google & Pivotal have been working on Kubo[0] to make the management of Kubernetes easier by using BOSH as the deployment/update/repair system. You make deployments by editing a yaml file. Or, better yet, but having a tool edit the file for you as part of a structured CI/CD pipeline (I've seen both and I am a fan of the latter).
BOSH works at the IaaS layer. Insofar as you mean "spin up and down VMs", Kubo is well-suited for that exact problem. You also get a bunch of upgrade and self-healing stuff for free.
Pivotal is also adding a commercial offering based on Kubo, PKS[1], which has been built with Google[2] and VMWare[3]. You might not need it for your exact usecase; the sweetspot is Pivotal Cloud Foundry users who want a relatively seamless side-by-side integration between CF and k8s. There's a bunch of value-added features (Harbor, GCP service brokers), of course, plus the whole throat-to-choke thing people like to pay for.
The pricing model isn't set in stone, but I suspect it will settle in the vicinity of what you have in mind. Our DNA is charging per-instance for Cloud Foundry apps, rather than worrying about sockets or RAM or other metrics which only poorly correlate to user value.
Anyway, I can hook you up with Kubo or PKS folk. Email me: jchester@pivotal.io
[0] https://github.com/cloudfoundry-incubator/kubo-deployment
[1] https://pivotal.io/pks
[2] https://www.blog.google/topics/google-cloud/vmware-and-pivot...
[3] https://blogs.vmware.com/cloudnative/2017/08/29/vmware-pivot...