A tough question, as I find that much of this material is a tough read as you noted.

I own the entire History of Middle-earth set, but never really look at them. What happened is that I bought the Book of Lost Tales and Book of Lost Tales 2 because I thought they would have more stories in them, and didn't realize they would be so technical. Years later I was in a used bookstore and saw the four volumes that pertain to LotR and thought, "that would be cool," and traded a boxload of used books for those four. Then later I saw the one with "Return of the Shadow" (the fragment of a LotR sequel) in it and had to have it for that story. Somewhere along the line I told myself, "well, heck, I own something like 7 of the 12 so why not have the whole set?" and bought the rest.

I guess I like the concept of being a Tolkien scholar, but lack the drive (and have poor memory) to actually become one. :wink:

I since bought the Children of Hurin and Beren and Luthien and Fall of Gondolin because I love the concept of having each as individual stories, but they mostly sit and collect dust.

So, I guess my example is to buy everything, but my advice would be to pick and choose carefully. Does that help at all?