I guess what you're eluding to here is some kind of membership levels, e.g. None, Bronze, Silver, Gold with different levels being able to see different articles/content within them?

I haven't tested or used this much, but the option to embed another Helpjuice article in a Helpjuice article may be beneficial here. However, it creates the need to have many small articles in some instances. Also, I'm not sure if the article you embed will only show for those users it's shared with originally, or those who can view the full article.