Remember to upgrade
A side-effect of having my hard disk crash while I'm half way 'round the world from my backups was a forced system upgrade. It went smoothly, and almost everything works as well (or better) than before. I'm an experienced user, of course, and even then I spent several hours getting everything just right, but operating systems are big and complex upgrades.
Changing the OS seems to have broken only one application (EndNote, my footnote manager). I'm writing a lot here in Singapore. So I went ahead and downloaded the upgrade -- something I'd been putting off for some time -- and again everything went well. Not only are the problems fixed, but the application works better than before.
Investing $89 in improving a tool I use all the time is common sense. Software upgrades are a bargain.