Do you think that this means that they've levelled the inefficiencies of used books out of the market? That is, mostly everyone who wants a book can get it, and the scarcity of right-book-right-place-right-time that added to the price in the past is now gone?
About 10 years ago I bought a pretty obscure book, and noticed that it said "Volume One" ... I poked around and didn't find anything about a Volume Two. Last year I looked again, and there it was. And there were four copies available, one of them in mint condition for less than I'd paid 10 years ago for Volume One.
/jordan