If it fixes bugs from former versions, what choice do you have?
Unless bugfixes are given seperately too.
I have no problem paying for serious upgrades, but not if I very recently
purchased the newest version
.

Exactly.

As to skipping upgrades, once I find software that I like and come to depend on, I tend to get most if not all upgrades so I have all the tools to work with and stay current with tutorials, etc.