All other things being equal–do you prefer used books? Or new books? (The physical speciman, that is, not the title.) Does your preference differentiate between a standard kind of used book, and a pristine, leather-bound copy?
It doesn’t matter to me really, as long as the used book is in good condition (aka, minimal wearing of the spine, binding still in tact.) In the end, it’s the same book and sometimes going used is a great way to get more books for your buck. Also, I have a great used book store in my area and every couple of months I trade in some I’ve read and don’t plan to read again and get trade credit.
I don’t collect a lot of books so I’m not too concerned with leather bound editions, though they probably look nice on a book shelf. About the only collectible books I have are some autographed copies of some favorite books that I keep together on a shelf. I’ve made sure that my family knows if something happens to me, where they are and which ones they are.