If you can afford it and it brings you enjoyment and you have adequate storage area for them, then if you enjoy buying books, buy them!
I have had to be frugal with my purchases. There are many times when I want to go to a bookstore and purchase lots of books that I’ve wanted to read or have heard are enjoyable. But I’m far away from stores, so it’s not as much temptation. Also, the family budget curbs my spending. I’d much rather use the public library and their ebook system (Libby app) to read a book. If I really enjoyed the book, I would then buy it.
It saddens me when I see people who buy books and then the books aren’t stored properly; their spines and covers and pages get damaged. It’s just like shoes, clothes, purses, cars, knickknacks, etc.: if you don’t store them properly, they are disused. Treat your belongings well.
Some authors have favorite phrases for different sexy times. I can’t recall specific ones at the moment, but Julia Quinn uses some phrases quite a bit. Lisa Kleypas does, too.