While researching Houdini material at Abebooks.com, I came across the following listing that you can own for $65,000 plus $4.00 shipping:

CANCER OF SUPERSTITION, THE.” Autograph Manuscript (AMs). 19 leaves. Not dated, but circa October 1926 Lovecraft, H[oward] P[hillips] and C[lifford] M. Eddy, Jr. 

Description:

Lovecraft’s handwritten outline (published in THE DARK BROTHERHOOD) and Eddy’s handwritten and typewritten drafts of the first three chapters are extant. This 19-page handwritten manuscript, edited, revised and copiously annotated by Lovecraft, is Eddy’s draft expanded from Lovecraft’s handwritten 4 1/2 page 12-part outline (held by Brown University). It is the version from which the typescript sent to Houdini was made (that typescript, missing three leaves of text, was sold at auction by Potter & Potter 9 April 2016 for $33,600).Eddy’s manuscript is divided into three chapters. Chapter I, “The Genesis of Superstition” (leaves 1-8 of this handwritten draft), published in a slightly altered version in THE DARK BROTHERHOOD (1966), pp. 250-61. Chapter II, “The Expansion of Superstition” (leaves 9-14) and Chapter III, “The Fallacy of Superstition” (leaves 15-19), currently unpublished, comprise the remainder of the manuscript. Part of the manuscript is written on the versos of various discarded drafts, several of which are of considerable interest: (1) verso of leaf 2 is a draft of a letter from Eddy to Houdini, 15 October 1926, asking if he had received “the synopsis of the proposed article on the origin and fallacy of superstition” and if “the requested advance check for $15.00 is on the way together with whatever you wish to offer in the way of annotations & suggestions” (2) verso of leaves 3 and 4 have an earlier draft of “The Cancer of Superstition” (3) versos of leaves 5-8 have discarded pages of a crime story by Eddy (4) verso of leaf 9 is a draft “Questionnaire — Oct. 19, 1926” directed to Houdini about the scope and direction of the “proposed article which you assigned me, while in Providence, on the origin and fallacy of superstition,” and requesting his input (5) verso of leaf 10 is an expanded draft of the “Questionnaire” (6) verso of leaf 14 has a long continuation of the text from leaf 14 in Lovecraft’s hand on a discarded earlier draft of leaf 13. The verso of leaf 1 has the beginning of a letter dated 12 October 1926 to the Boston Sunday Post; the versos of leaves 11-13 and 15-19 are blank.H. P. Lovecraft met Clifford M. Eddy, Jr., a native of Providence, Rhode Island, a published writer of popular fiction and student of mythology and the occult, in 1923 (their first face-to-face meeting, after an exchange of letters, was in Providence at Eddy’s home on 9 September 1923). Lovecraft, who met Houdini in New York City in 1924, ghostwrote Houdini’s “Imprisoned with the Pharaohs” (aka “Under the Pyramids”), published WEIRD TALES in 1924. In 1926 Houdini hired Lovecraft to write an article attacking astrology, for which he paid $75 (the manuscript of the article, which does not appear to have been published, was sold on eBay in April 2009 ). Then he commissioned Lovecraft and Eddy (who may have done work for him at an earlier date) to jointly ghostwrite a full-length book on superstitions. According to Eddy (handwritten statement dated 9 June 1962): “Back in the middle twenties both H. P. L. and I were doing ghostwriting for the late Harry Houdini. Shortly before Houdini’s death, he gave me an assignment to do a complete book for him on the subject of the origin, growth and fallacy of superstition. He furnished me with voluminous notes and ideas that he wanted incorporated in the book and suggested that perhaps H. P. L. whip them into some shape that I could use as a guide. I wrote the first three chapters of the proposed book. The first two were read and approved by Houdini, and the third was in the mail, addressed to him in Detroit, when he was stricken with the appendicitis attack which resulted in his death. About a month after her husband’s funeral, Mrs. Houdini advised me that she would prefer to have the work on the proposed book abandoned. Whatever became of the the three chapters that had already been completed, I never learned. Sometime later, at one of our get-togethers, Lovecraft and I were discussing the subject… Bookseller Inventory # 155672