How Do You Price a Snappy Lunch?

Before my sister bought me a copy of Snappy Lunch, I went looking on Amazon to buy one myself. There were three sellers who had it - two used and one new. Each was over $300 and all were within a penny of the same price! I chose a life of piracy until I could find a more reasonable price and didn't think about it again until today when I saw this blog post by Michael Eisen. Turns out some complicated automatic pricing shenanigans are probably responsible.

My preferred explanation for bordeebook’s pricing is that they do not actually possess the book. Rather, they noticed that someone else listed a copy for sale, and so they put it up as well – relying on their better feedback record to attract buyers. But, of course, if someone actually orders the book, they have to get it – so they have to set their price significantly higher – say 1.27059 times higher – than the price they’d have to pay to get the book elsewhere.

What’s fascinating about all this is both the seemingly endless possibilities for both chaos and mischief. It seems impossible that we stumbled onto the only example of this kind of upward pricing spiral – all it took were two sellers adjusting their prices in response to each other by factors whose products were greater than 1. And while it might have been more difficult to deconstruct, one can easily see how even more bizarre things could happen when more than two sellers are in the game. And as soon as it was clear what was going on here, I and the people I talked to about this couldn't help but start thinking about ways to exploit our ability to predict how others would price their books down to the 5th significant digit – especially when they were clearly not paying careful attention to what their algorithms were doing.

Back to Snappy Lunch for a current price check.

Price	Seller
$67.95 + $2.98 shipping	teagan1116
$67.96 + $2.98 shipping	plan9music
$67.96 + $2.98 shipping	secondhandtunes

Automatic pricing. When it hits $13.95, buy!