It depends on the books and your rate of reading. I spend about $100/month on books which is often only 2 or 3. I can't always justify spending more. I would agree with you in the case of fiction, as the books are cheaper and better represented at libraries. But non-fiction is expensive, and I read a lot of technical and niche nonfiction.

I see. I mostly read history and fiction. I read a lot of technical books when I was trying to become a programmer but now it's often the last thing I feel like reading.