Step 1: Pretend you're a sophisticated bookworm.
Step 2: Find a book that's just out of your price range, but not so out of your league.
Step 3: Call the bookstore and ask for the book, but pretend you've never actually seen it before.
Add in a dramatic pause for maximum effect
Step 4: Negotiate the price, but only if you've already established that you're a "serious collector".
Step 5: Once you've got the book, immediately sell it on the black market for triple its value.
See how the pros do it: Selling books to gullible collectors