At Language Log, they’re having trouble with the economics of penumbral book trade pricing:

I’m still puzzled. I would have neither any moral nor any practical objection to the operation of supply and demand in such cases — but it seems that the supply is basically fine. The book is far from being out of print, copies are available from the publisher at list price, Amazon and Barnes & Noble will be restocked shortly… Perhaps there are automated pricing algorithms that scan the bookstore sites and kick in whenever an out-of-stock situation arises? Or do Amazon and B&N sell lists of books that customers ask for but they are (temporarily) unable to ship?

One glib answer: When the data don’t fit your hypotheses, how long should you wait until you question the hypothesis? Which is to say [quoting myself], “Who told you the economics of price formation was about individual cases, or even begins to apply in illiquid markets like books and collectible markets?” [to which could be appended numerous riffs on that subject, which I'm not gonna bother moving over from the Old Blog just now. Maybe to make a subtle point about access, bottlenecks, and change costs?]

Two more reasoned ones:

First, my wife’s, which is intrinsically smarter and more rational than mine: No doubt these sellers are using drop-shippers for their order fulfillment. That’s two layers of margin that need to be added to every item. Call that a 100–200% increase, in the end. People who do not know what drop shippers are, are provably not “more familiar with the book trade,” at least in the modern form appropriate to this situation. People in the publishing business, or bookstore owners, are I suspect left in the dark about how things happen in the penumbra.

Second, my edgier and (surprisingly) more succinct Complexological/Economological take: You see a price being asked. You do not see the price that has been obtained. If the person got 181–200% markup, and sold out, then clearly you would be wondering about the gougers asking 220% markups.

I can call high prices from the vasty deep.

Why, so can I, or so can any man; But will some sucker pay when you do ask for them?