I'm hesitating to update as I'm not finding the current features not enough to convince me to do so. However, if in the future if you can implement more animated graphics, such as those graphic pop-ups that I see so much in marketing videos, that would entice me to upgrade.
If you instead buy a "maintenance agreement" you can update whenever; cost ~ $70/yr for both Camtasia and Snagit. As a retiree, it's in my budget and I never have think about it. BTW, you can have 2 or more versions on Snagit or Camtasia installed simultaneously.