This reminds me of an actual story about book that was being priced at hundreds of thousands of dollars (I looked for a link to this story but couldn't find it)

This reminds me of an actual story about book that was being priced at hundreds of thousands of dollars (I looked for a link to this story but couldn't find it). The gist was that a feedback loop from two online book sellers, neither of which had a copy of the book. They automated the pricing such it was based on the other's listing plus a small markup; the idea being that if someone wanted this book, they could buy it from the other seller, add the markup and pass it on the customer. But since both were doing this, one would see the price add a markup and set it as their price. After a while, the other would then see this price and do the same thing. Over time the price just grew and grew.