Personally, I still prefer paper for certain kinds of non-fiction, but not because they are collectible objects, simply because they are easier and more enjoyable to read (for example I have never enjoyed the cookbook e-experience). As far as books as 'objects' go, the only ones I have are the vintage A.A. Milne my grandmother used to read to me, and as my first sort of decorating/buying art purchase ever, I had an art student design and make for me some shadow box frames for them to properly protect and display them. But that was done not so much as a 'collectible objects' thing and more because it is a very strong memory I have of my ailing grandmother, and I was seeing these books as my big memento of her. I did not want them moldering on a shelf, I wanted to display them as a memento and give them the tribute they deserve. Fwiw it was about $100 per frame (there are three of them) so $300 total, which was quite a lot for me. But now that I have them and they look so beautiful and I think warmly of my grandma every time I walk buy, it was totally worth it and I will treasure them.
But as I said, that was more about honouring my memento from my grandmother. They could have been something else instead of books, that just happened to be our particular thing. You can see pictures
here if you want to.