They were described by the seller: "[these] may be the only remaining materials reasonably describable as 'manuscripts' to have been preserved from among his effects at his death in 2003, and it was only by chance that these survived. They were salvaged from the rubbish-bin by the husband of Blanchot’s long-time housekeeper." All were priced accordingly.You can read the answer yourself. It includes a description of the content of the book itself:
An appealing story, and sure to whet the collector's appetite with its claim of extreme rarity, a 'last chance' to own a piece of one of France's most important literary theorists. Was it true?
L’Entretien infini is a book largely constituted from work written between 1958 and 1969. The book crosses disciplines (literary criticism, philosophy, and political thought) and genres, presenting a series of fragmentary dialogues (with anonymous interlocutors), meditations, and complex arguments. It is widely considered his theoretical masterpiece, and the proofs bear witness to the reformulations of Blanchot’s thought during this period: his continuing search for a form through which to express them.The conversation also reveals the minor, indirect influence a certain literary blog had in starting the process of acquiring the manuscripts. (Link via Charlotte Mandell).