I got that thought, loud and clear, while reading John Baxter's A Pound of Paper and it's incredibly true. A lot of places I visit to get books have a blanket "50 cents for paperbacks, a buck for hardbounds" rule. But the used bookstores are another thing. The owners pride themselves on their knowledge of this-or-that writer, edition, publisher : whatever. But they don't know everything about everything and it's really surprising how little they know in my area about Hunter S. Thompson for example.
I went to Bennies and was really pissed when they only took my Orwells, but I found a copy of Fear and Loathing in Las Vegas there for $3.50 and it was a 1971 Popular Library edition. Hell, I instantly recognized a possibility there and took it for store credit. Of course store credit means that I took to Bennies dozens more books, some I actually paid real money for, and they "gave" me credit and I had enough credit to get this book as well as two others. But I really wanted the HST and once I got home posted it online for $3.85 (to prove a point to myself, I guess) and it sold for $21.50 (proving a point for myself, I guess)
Yes! A slightly bigger student loan payment this month. I can almost feel the interest falling!