Every time I see this - and I see it a LOT at Amazon - it always annoys the hell out of me. "Authors" or "Publishers" who basically take the entire text of a book off of Gutenberg or elsewhere, add nothing to it, and then put it on Amazon to sell.
Example: Waxkeep Publishing
Book on Amazon: The Confessions of Jean-Jacques Rousseau
Cost: 99 cents
Book on Gutenberg: The Confessions of Jean-Jacques Rousseau
And you can chose the version with or without illustrations.
How do I know both are the same? By the preface in the beginning of each of them, which is dated 1896, by S.W. Orson. If the publisher can't bring me a new translation or anything different than the Gutenberg text? Why am I paying them money for the book?! Some "publishers" may add a bit of formatting or some images and then call it a special edition - doesn't impress me, they're still charging money for very little work or scholarship. And it is indeed cheating the reader who may not know Gutenberg exists.
While .99 doesn't seem like much, I see this constantly and with prices as high as $3 and up. And always for classic books that are offered elsewhere for free.
What can you do to stop this kind of thing? In theory you can contact Amazon, which is supposed to have its own version of every public domain ebook but doesn't always. But honestly what you can do for yourself is this - bookmark these pages:
If you are looking for older books always try searching those sites first. There are usually multiple formats available for download free, and Internet Archive contains most of the books Google scanned from libraries.
Another option is Open Library - if it doesn't have a downloadable version, it may have an ebook you can check out for two weeks, like any other library.
There, now I feel much better. I was hoping for a more modern translation though. Humph.