It took me too long to understand this, but I'll toss in one exception to your rule: storage (short term and long term). I've found that it's frequently useful

It took me too long to understand this, but I'll toss in one exception to your rule: storage (short term and long term). I've found that it's frequently useful and economical to upgrade long term storage; eg. the HDs/SSDs until recently were on a price curve such that you were better off postponing buying more until you needed it. And quite a few of my systems have gotten a RAM bump midlife (where prices had come down). Alas, as more as more systems now come with soldered down memory, I usually max it out for longevity.