Well, I think it's good to borrow books from the library but it's a must to buy books so that you can keep.
My problem in finding books from library:
1. some books are old, torn, small bad....
2. even I searched it on catalog, I still couldn't find it on the shelf. I even searched the books to be shelfed cart.
3. alternative is reserve the book through Internet, but has to pay and reserve it in advance. That means go to the library one more time.
4. usually I renew the book through Internet the last day. Sometime I found the book was reserved and must return the same day to avoid late charges.
So, now you will feel better that if you buy the book, you can keep it, read it any time, as many time as you'd like,......... It's worth to spend the money provided that your sweety loves to read.