I was on amazon.com today looking at a list of sources and prices for a certain used book. The used booksellers list for a certain book was arranged from lowest price to highest price. At the end of the list I see a price of $ 688.88. There are two entries at that price by the same used book seller. The price just above that is $ 35.80 which is at the 28th spot on the list with the first spot being $ 6.25. The book is titled, Emerson : The Mind on Fire by Robert D. Richardson.

Here's what it says for the used book being sold for $ 688.88. The Seller Rating is 5 solid stars.

Seller Rating:99% positive over the past 12 months. (1,414 total ratings)
In Stock. Ships from IL, United States.
Domestic shipping rates and return policy.
A standard used book. Highlighting/writing throughout the pages (more than 100 pages).? Many pages are bent, and about 15 of them has small tears on the corners. Shelfwears on the corners of the book. Binding slightly loose. Book still very usable and readable, though. No water damages in the pages. No loose or missing pages.
I've seen this before on amazon. Is it just that there are some people that like to throw their money away or they have so much that they feel they have to use it up? Or maybe the seller is conducting an experiment to see if anyone purchases at that price? I've heard of experiments being done where they give a money back guarantee for a book or course or something and then purposefully ship blank pages of paper to see what percentage of people will ask for their money back.