I love the Far Cry series.
Personally, I think they do a lot of things right in these games, and I've always enjoyed the experience. I see all the FC games as superior AAA titles.
That said, I absolutely find these games, and the experience, to be worth the full price. They've been day 1 purchases for me. Far Cry Primal was no exception, and when I completed it I had no regrets.
Now.. if you're not that into Far Cry.. it might not be worth the same to you. Just wanted to point out that these games, including Primal, have definitely proven their worth to me.