Overall, I guess I would say that Office 365 isn't a terrible deal, though I think some smaller business are probably better serviced by buying Office on disk and running it until it fails to meet their needs. The cost of Office for consumers, and students is pretty inexpensive, but I'd still maintain many of those folks would be just fine with Libre Office. One of the concerns I have with software as a service, is that I can't shake the notion that the publisher is likely to suddenly shove a railroad tie up my wazoo.
I think we've already seen this happen with Adobe's pricing of Creative Cloud. Last summer, Adobe ran a deal where a student could get a discounted subscription for only $24.95 a month, but the program required validation of eligibility, and Adobe ran it in the summer. very funny, Adobe. Right now, they have a deal until the end of the month where you can subscribe to Photoshop and Lightroom for $9.95 a month, and then after the contract expires, the subscription goes up to the going rate if you choose to stay. So, I bought Elder Child a subscription, since she's got some Photoshop experience and might have some fun. I also told her to that this would most likely only be a one year experience.