I only buy paper books if they are truly unavailable in e-book format, OR the book is exorbitantly expensive as an ebook (and the book is rather short).
I have fund I really have little patience for paper books. Yes, they're nice and classic, but I was never a big reader before buying my Kobo because they're terribly inconvenient to carry around. I also have the terrible habit of checking how many pages are left until the next chapter
but my Kobo just tells me at the top of the screen.
If I do buy a paper book, it's gonna be secondhand and/or a book I need for reference. Also, non-fiction only. The paper books I own are mostly Japanese reference material, some spiritual reading/bibles, a good amount of photography books (photography ebooks never look as good). And that's about it. Everything else is on the e-reader.