Many if not all rare book vendors list on Amazon. When you search for a book by title that's been in publication for a long time you will therefore get results that include current editions AND old rare editions that are collected at a much higher price.

That's all that happened here: Amazon sells both current books and old rare books from dealers of rare books.

Old racist titles are sold for big bucks because people collect them, most notably lots of black people..I know rmrd knows this, that black collectors of racist collectibles are the main ones that push prices high.

Here's the old rare version of being sold on rare book collector aggregate site Biblio.com. Note they have now added the politically-correct provision that any racist books they offer, they donate the "profit," (or their commission) even though, like Amazon, they are not the actual seller but just a platform for sellers

https://www.biblio.com/ten-little-niggers-by-christie-agatha/work/290352

Obviously you can see from the prices that the original title is very rare and therefore valuable, most of them destroyed, hard to find.

If you scroll down you will see fascimile editions recreated in plain cover for scholars who might want to study the original edition of racist books. They are not mass marketed, not "published" in the usual manner, these are often made by people who also reprint other old out-of-print books for scholars who can't afford the collectible version.

This is exactly the way books like "Mein Kampf" by Adolph Hittler is sold if you do not want an annotated version. And unpublished PHD theses for that matter.

Edit to add: it is common for facsimile and reprint makers of out-of-print books to list on Amazon too. You will get therefore get their offerings if you search for a title as well. They are not mass market publishers, they cater to people who need to have an older version of a book and cannot get the older version because it is rare. They are usually plan text and plain cover, though if illustrations are important to interpretation some might offer that as well.

Yes genius Mullah Omar's narrative of history to be taught to all citizens did not include human imagery nor Buddhism, not to mention his genius interpretation of the narrative of Koran prohibited not just music-making but kite-flying...