Where did the bookstore get those cheap books?

I often see very cheap (45% discount) books for sale in online bookstores or physical bookstores (and they are all relatively new books). May I ask where the bookstore bought these books? If it was sold to consumers at such a low price, wouldn't their purchase price be even lower? Usually, their purchase price would be a few folds of the price listed on the book. Thank you!
What was the main difference between purchasing from a publishing house, a bookseller, or a wholesale market? What were their advantages and disadvantages (for example, the price of the purchase, the amount of purchase, the difficulty of purchase, etc.)? In addition, could they purchase directly from the printing factory? (Does it involve copyright issues? Can't the printing factory purchase?)
Please answer in detail, thank you!

Answer 1

Bookstores usually buy books from a variety of sources, including second-hand bookstores, online bookstores, publishing houses, wholesalers, and so on. Second-hand bookstores were one of the sources of books that bookstores often bought because these books might be books that had been disposed of or were no longer for sale, or books that were being sold in other bookstores but had expired or were no longer popular.

Online bookstores are another common source of purchase. These bookstores usually offer lower prices than traditional bookstores because they can receive books faster and sell them through online sales platforms.

In addition, some publishing houses would also take back some books that were no longer on sale and republish them. These books would also be sold to bookstores at a relatively low price.

Therefore, bookstores could buy books through a variety of channels, including second-hand bookstores, online bookstores, and recycled books from publishing houses to get a lower price.