Also, since it seems that PS Now users are upgraded to Playstation+ Premium at no extra charge despite the service being more expensive, if you bought 12 months of PS Now right now you could probably get PS+ Premium at nearly half price. Of course you can no longer buy it on the PS Store, but you can still get gift cards which I assume they wouldn't just stop accepting. Of course whether or not that bump in price is justified in the first place is hard to say before we know more.
Edit: The "bump" I mentioned is actually just the combined cost of PS Now and Plus, so yea if you only had PS Now, it seems you would get Plus added in for free.
I may do this myself, I was just thinking about that very same upgrade path. Buy PSNow this week, have it upgraded to a year of premium at half price overall. But I am not sure I will even be using the premium tier anyway, since PSNow never interested me in the first place. I will need to see them do more before I consider anything more than that method.