Both of our sellers were happy to share their favorite places to shop. Lori says, “Library book sales are my number one source. Often the prices are deeply discounted on the last day of the sale, and you can acquire a large number of books for not very much money – plus you can feel good about supporting the library. I also routinely check Craigslist, where people often sell books low-cost or give them away. You have to be careful going that route, though. A few times I've gone out of my way to pick up a free lot, only to find that the books have been stored in the basement and are hopelessly moldy.”
Auction sites online and auction houses are also worth checking out for second-hand books. House clearances can be a good source of book collections. Often relatives of the deceased just want to clear the house with as little hassle as possible. If you have transport you may be able to be paid by executors to take hundreds of books away for dumping, and retrieve a couple of gems from the dross.
Of course, there are plenty of other ways to go about this: you may want to do the KonMari method, you may just go for a good ol’ spring cleaning. You may need to recite some of Alice’s helpful mantras to yourself. However you do it, you will hopefully be left with large stacks of books to dispose of. You could give them away or donate them, which is quite noble, but it is always nice to be able to get a little money back from everything you’ve paid out to your bookshelves.