Nah, it can be stupidly expensive to go to a binder. But pasteboard and some fabric plus stencil letters is fairly cheap. You can rebind a book for about $10 or less.
(admittedly not perfectly, but enough to look good and last).
It started because a group of us at uni found out we really really love books, it was a bit of an addiction actually, so we started our "libraries" for a bit of fun.
Originally we were meant to have read every book for it to count :) but that quickly became impractical. I have about 6,000 books (most in boxes, sadly, till I find a bigger place) but that is small compared to some of the group :)
Not always a recommended hobby; it is impossible to walk past a second hand bookshop now, and they are surprisingly common :)
I also really like books. Some time I will write a bit about my experiences as a (online) bookseller. A lot of the attraction was having all these books. At my peak, I had more than you do. When I dumped the business I cut back to a reasonable number (and they aren't in inventory anymore, so I can't tell you how many I have.)
Personally, though, I'd rather spend time reading the books than rebinding them so they look nicer.
but yeah, I can understand the want to collect books, even books that you likely won't have time to read. But, I mean, if it's not something you are likely to read, it's more of a collectible or decoration than a book, especially if you are going to put a lot of labor into making them look good, which is why I say it sounds like a display of wealth.
wow, that sounds expensive. On the other hand, as far as ostentatious displays of wealth go, that sounds like one of the more classy ones.