: "Goodwill Bins" (Goodwill Outlet) often sell books by the pound or at extremely low flat rates (e.g., 10 books for $1).

: Contact local estate sale companies or independent bookstores going out of business. They are often eager to sell large quantities quickly to avoid disposal costs. Specialized Comparison Tools

: While not a direct bulk seller, it is the best platform to compare prices across 30+ vendors if you are buying specific titles in quantity.