Get a copy by other means, then list it on Amazon for slightly less than the cheaper ("legit") seller and order it from the expensive ("scam") one, hopefully before they adjust their prices. Then the scam seller buys it from you to sell to...you, and you pocket the difference.
This will presumably only work if the scam seller also automates the actual purchasing. If there is a human in the loop, they may look elsewhere for a copy and you will be out 23 million dollars (but have a copy of the book).
I would assume most Amazon marketplace sellers won't have the liquid assets with which to automate a 23 million dollar purchase.
I got frustrated once that my local supermarkets carried all but one particular flavor of a certain (food) product. So I looked on Amazon, and somebody was selling a moderately large case at an inflated price, and I bought one, because there didn't seem to be another option. Within a few weeks, I see the same thing on the shelf at a local store, substantially undercutting what I paid. Then, however, they never restocked it.
It wasn't like I was planning on starting a business of reselling it, but it was startling.
Which is exactly what the article's author thinks might be happening, for the higher-priced book.