I save my down loadables to an external hard drive. But, You can also save patterns to a memory card. My Kindle does accept memory cards.
As for the printing, it is expensive and takes up space. I try (operative word being try) to print the template part of the pattern as I want to make the pattern. I use less paper and ink that way.
I sometimes will buy some craft/quilt books from Amazon when they are a steller deal for my Kindle. If I really like the book, I will wait until I can get a second hand copy of it at a good deal. Sometimes, it saves me from buying a hard copy book that really doesn't meat my needs and just takes up space.
Although, Annie's pattern books are usually exclusive and some are out of print. So, it is the only place you can buy them. I have a few. It's not the same as holding a book though.