D1 and D4 are on sale on playstation. Are they worth it for the story alone?

I'm currently deep in D7 postgame and I'm not leaving anytime soon. I'm just thinking that D1 would be really nice to have seen once so that I understand all the references. For example a lot on this subreddit, or any of the DLC characters in D7.

They are both €25 currently. Would you say that's worth it? I guess I could be done with the story in 20-30 hours? But if the stories are really good that's alright for me.