Seven Footprints to Satan, by A. Merritt (HC, 1928, $10, which is 1/3 the current internet price.)
Merritt wrote early pulp "fantastic fiction". He was one of the best paid writers of the time ($100,000 a year), but put out only a limited number of books. Several of his books were made into movies. Seven Footprints was produced in 1929 (?), both as a silent, and a partial talking movie. For many years the movie was thought to be lost, but eventually a poor quality Italian silent version was discovered.
The plot is simple... until it gets complex. The hero, Jim, is about to travel to Africa, when his fiance asks him for help. This leads to their being kidnapped by satanic jewel thieves. The movie is supposed to include orgies, scantily clad women, and weird characters, all filmed with an art deco flair. Whether or not the book also does this, you will have find out for yourself. You can find this book (along with its photos of 8 scenes from the "photoplay") in the HC fiction section, avail. 10/19.
(Note: if you ever get a chance to see the film, watch for Loretta Young as an uncredited extra!)