Book price puzzle
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On amazon.com yesterday:
\$33,634.25 for a book that's in 464 libraries, and is available on abebooks.com for \$17.76 (at least it's not \$19.84 :-) or \$49.00 plus shipping?
I've seen unreasonable amazon prices for out-of-print books before, but in the thousands of dollars, not the tens of thousands.
Is this an out-of-control re-pricing bot? Or a money-laundering scam? Or what?
On amazon.com today:
So either the bot calmed down, or the scam went through.
Ross Presser said,
December 21, 2022 @ 9:16 am
In the past, such out of control pricing has been due to two independent pricing bots feeding on each other.
Carl said,
December 21, 2022 @ 9:40 am
To piggyback on what Ross said, sellers often list books they don't own if they know they can buy it from someone else after an order has come in. This is a variation on https://en.wikipedia.org/wiki/Drop_shipping . When two such listings are placed, they can spiral out of control as bot A thinks it will buy the book from B and add a 10% markup, while bot B thinks it will buy it from A and add a 10% markup.
Aaron said,
December 21, 2022 @ 9:44 am
Matt Parker has a video about exactly this phenomenon, which should explain it to your satisfaction: https://www.youtube.com/watch?v=sseSi0k3Ecg
Terry K. said,
December 21, 2022 @ 9:48 am
In Amazon's data as two different editions. And when I find one and click on "See all formats and editions" it shows both, with those prices. (I guess Amazon's software doesn't recognize that "1st" and "first edition" in the edition field mean the same thing.)
Matt Sayler said,
December 21, 2022 @ 11:00 am
https://keepa.com/#!product/1-B0006AVNSW shows price history, which is pretty wild (click "all" on the right under Range to see ~5 years)
The price was reasonable, about $11, until November 2020, when it first spiked to $850. There was a huge spike to $38K in July 2021, and what I suppose is bot-driven volatility last winter.
Terry K. said,
December 21, 2022 @ 11:09 am
Just looked, the two copies under the \$33,634.23 listing are only 91 cents apart in price (the other copy available on that listing being \$33,633.32.
Terry K. said,
December 21, 2022 @ 11:22 am
Apparently, we shouldn't copy/paste prices with raised dollar signs. Which the blog software is apparently taking as some sort of math thing.
That should be:
Just looked, the two copies under the \$33,633.32 listing are only 91 cents apart in price (the other copy available on that listeing being \$33,633.32).
Terry K. said,
December 21, 2022 @ 11:24 am
Nope, did it with a typed dollar sign too.
[(myl) Fixed now — see https://docs.mathjax.org/en/latest/input/tex/html.html
tl;dr just prefix dollar signs with backslash to avoid triggering mathjax…]
Dagon said,
December 21, 2022 @ 12:04 pm
I can still see the expensive one, alongside the more reasonable one.
I suspect it's less nefarious and not even as technically interesting than the options you mention. I'd bet it's a cut-and-paste error in the listing feed. Even today, a lot of sellers on Amazon literally upload a human-curated spreadsheet of product details and price. And sometimes they transpose a column, and put their sku or other identifier in the price field. Hilarity ensues.
Or perhaps it's legit – that one does claim "first edition", though I don't expect it's famous enough for that price.
AntC said,
December 21, 2022 @ 4:43 pm
bot A thinks it will buy the book from B and add a 10% markup, while bot B thinks it will buy it from A and add a 10% markup.
Sounds like how crypto exchanges inflate their alleged worth. Except with FTX, it turned out to be buying from itself (via a deliberately obtuse chain of intermediaries). Another example of 'how could such clever people be so stupid?'
Kaleberg said,
December 22, 2022 @ 12:18 am
This happens from time to time. My favorite was back in 2011 with a $23,698,655.93 textbook on insect development that was the result of two bots. The one run by the guy with the book undercut the highest price by a few points while the one run by the guy who was going to buy the book from the first and sell it with a markup added that markup. Oh, that was $23,698,655.93 plus $3.99 for shipping.
Paul McCann said,
December 22, 2022 @ 3:40 am
I've seen one other cause of weird high prices on Amazon besides simple pricing bots. Sometimes there are bots that automatically list things which would be shipped from overseas, and factor in shipping prices calculated arbitrarily, even when it doesn't make sense (so the price, not the listed shipping, is affected). This can turn a 3USD pack of hot chocolate into a 300USD listing in another country. I've mostly noticed it with inexpensive food items, where import availability is hit or miss, but it can affect all kinds of products.