I would say that I have got quite a good collection of books to use as references. Yet with some exceptions, a lot of these I've acquired quite cheaply. Reason? Simply their condition.
This one I haven't got round to sorting photos of the pictures yet. It was a pretty good example of one of my 'cheap' buys (though I confess I can't remember how much I paid for it.
Firstly, it's not a book, it's a photo album. Which probably put off a lot of potential buyers. The condition of the front wouldn't help.
Firstly, not obvious but the spine was completely detached on one side. Not obvious now because I glued it back. Really high tech repair.
Next, the album should have a clasp. Nope, gone, but... who cares? Well, the people who would have paid a lot of money for this if it had a clasp for a start. Me? Not bothered. Nor am I bothered that some of the cells where you insert photos are in poor condition.
So why did I buy it? For the pictures of course. Undated, but look to be 1880s-1890s. And the artist? Looked him up, Richard Caton Woodville Jr. The link shows why the album was a pretty good buy. (Update - Actually didn't mention what I paid for it... £5)