Just out of curiousity...
Does anyone shop at Half Price Books on a regular basis? Do you find it to be a good source for new reading matieral? Do you generally go to browse, or do you come armed with titles and authors? Do you often sell back the books you've finished? Have you found somewhere else to buy new-to-you books that is less expensive?
I was there recently and purchased a book I couldn't find in my library systems. I am pondering, after I've read it, whether to pass it on or sell it back as "down payment" on a new book. (If it's not worth keeping, which I don't expect it to be.)