Would I actually move off VMware right now?

If I were staring at a VMware renewal that had doubled or tripled, I would absolutely be looking at alternatives. I would also be pretty reluctant to approve a migration based on the invoice alone.

The easy part is listing options. Hyper-V, Proxmox, Nutanix, a move to public cloud. You can spend an afternoon putting those into a comparison table. What takes longer is finding out how much of your environment quietly depends on VMware behaving exactly as it does today.

The expensive parts are rarely the virtual machines

Say a company has 150 VMs. The guest operating systems may boot perfectly well somewhere else. Fine. What about backups? Storage snapshots? Network configurations? Your recovery process? The scripts the team has written over the years? And, importantly, does anyone on the team know the new platform well enough to troubleshoot it at 2 a.m.?

I would split the environment into groups before making any promises. Ordinary application servers and test environments first. Stateful systems and anything with unusual licensing or recovery requirements later. Move a representative slice, restore it from backup, break something on purpose, then decide whether the economics still work.

Sometimes the answer will be to migrate. Other times paying the renewal for another year is the less expensive decision, even if everyone hates the price. I would rather defend that decision with numbers than spend six months replacing one problem with three others.

The part of the quote I would dig into

Before deciding to move, I'd want the actual renewal terms and a list of every system tied to the current setup. Not just the virtual machines. Backups, recovery tools, monitoring, networking and the process for restoring a host when something goes wrong all matter. Sometimes a team has a perfectly workable alternative to VMware on paper but relies on one commercial backup product that doesn't support it properly.

I'd also split the environment into two categories. Some workloads are ordinary enough to migrate without much drama. Others are awkward because of licensing, special hardware or a vendor who only supports one virtualization stack. There is no rule saying both categories have to move at the same time.

A small pilot is more convincing than a slide deck. Move a low risk service, test restore procedures, rehearse a rollback and ask whoever will be on call whether the new platform is manageable. If the only person who understands it is the consultant who installed it, you've traded one problem for another.

My view is that a renewal can be a very good reason to rethink the platform. It should not be the thing that decides the architecture by itself.