In the case of MS Office I have no reason to pay for either version. My word-processing and spreadsheeting is all personal; no need to interface with a collaboration culture wedded to the Microsoft platform. I've been using Pages and Numbers for many years. Yes, they're different than the MS products, but frankly, I was more than done with the MS UI and its infinite array of features I never needed constantly cluttering the toolbars and menus. MS's need (and it's a rational need from a business standpoint) to deliver any and every feature some small niche of its user community required does not align with my needs. Pages and Numbers have never lacked for a feature I've required.
Sure, back when I was exchanging manuscripts with book editors there was no doubt that I had to use Word. Any incompatibility in the underlying markup language could break the editorial/layout process. Since I've been free of that particular workflow for nearly 20 years, good riddance!
I went from working with other publishing houses to running, authoring, and editing for a small, closely-held press. My partner and I moved to a different workflow - authoring/editing directly in Adobe InDesign. Our layouts were very carefully wrought, so write-to-fit was the rule of the day - no allowances for verbosity unless a particular section required bulking-up (a rarity). It was much easier to work directly in the layout than to craft templates for Word that could then be poured into InDesign. For simplicity I would write new sections in Pages or whatever was handy. So long as the app had a good word count/character count feature I'd be able to meet the preliminary budget. Fine-tuning would then take place in InDesign after a quick copy/paste.
As we were a small organization, the high cost of InDesign became a factor. My partner tended to delay software upgrades until circumstances demand it. I tend to be an early adopter. I generally lost the upgrade debates in those days due to the high cost of the Adobe suite. The trouble was, there was nearly always a crisis when an upgrade was finally necessary. For example, an old Mac would finally give up the ghost, and the new one couldn't run that old version of InDesign. Not only was there the usual pain of recovering from a computer crash/moving to a new machine, but there would be all those manuscripts that required conversion. Even if the process was 99.999% perfect, we still needed to scrutinize for any imperfections.
My feeling was, pay the cost of upgrading every year. Year-to-year conversions tended to be far more trouble-free. Rather than adapt to many years of accumulated changes in a single gulp, we could adjust to a smaller list of annual changes. Further, conversions on the file side were far less likely to be problematic as well. Focusing on the cash-dollar cost of the software can blind you to the far larger cost of crisis management.
When you compare the cost of upgrading one seat of Adobe to, say, that of maintaining/operating a delivery truck... I'd much rather be in a truck-free business. But partnerships are partnerships, and I always lost the annual upgrade debate. Until Adobe unveiled their subscription pricing. The math (run very quickly in Numbers) was clear. The cost of subscribing to CS was equal to or lower than what we'd been paying to periodically jump from one "perpetual" version to the next, even allowing for the gaps between purchases. Even my partner was convinced.
Office is cheaper than Adobe CS/Creative Cloud, but from my standpoint the principle stands. Subscribe and stay up-to-date at all times - it's easier and cheaper to adapt gradually on an annual basis than to face the occasional earthquake that a multi-year software jump can trigger.
Of course, there are software vendors out there that abuse the subscription model, forcing a higher cost onto subscribers than they'd have encountered in "perpetual" purchases. Of course these companies no longer offer a one-time price at all (offering both pricing schemes tends to keep pricing honest). Do the numbers, and if they stink try to find an alternative to their product. If there is no alternative you've discovered why they're gouging in the first place.