The “luxury item” designation only partly applies to price. Again, content, appearance, etc.
Maybe it’s the way I was brought up. Reading wasn’t a luxury, it was mandatory. My mother was a school teacher and we read books, LOTS of books. Perhaps if you think of it as a luxury then other mundane things will take up your time.
Most of my great finds for cheap are books on the must read before you die lists. Pulitzer prize winners, recent best sellers lists, classic fiction, History, autobiographies, politics, mysteries, thrillers, modern classics, and many great world lit works. I don't waste my time or money on poorly written books.
Living in a college town with a master of fine arts program does have it's bennies. ;)