In my considerably less-than-humble opinion on the matter, instructional books--digital vs. dead-tree doesn't matter here--should come in one of two prices:
A.) Free (and by "free" I mean "Free as in Richard Stallman buying the beer")
B.) Something between $20 and $25 (2010) US dollars per printed pound.
In my case, I mean computer programming books, (What else would you expect here?) But in all cases, the value-add of instructional books is multi-level. At the base, someone had to master the subject well enough to explain it to someone else. Built over that, that same someone had to have the additional (and much rarer) talent to break the subject down into chewable, digestible bites for folks starting from zero. (And, of course, that someone had to scrape together the wherewithal to write and publish the material.)
But back to the price-points.
"Free," whether we like it or not, comes with a "pay it forward" kind of obligation--at least after we've invested enough of our disposable time and attention-span to extract significant value from "free." At a minimum, we can recommend the material to others seeking the same skills, and thus give the author the recognition that s/he was presumably seeking by giving away her/his work.
A heftier price-tag, on the other hand is a healthy thing for the would-be purchaser (assuming that the work doesn't suck of course). With the odometer of software versions flipping so quickly, with new languages/infrastructures continually sprouting (and, sometimes, dying off just as quickly), the book purchase is almost a commitment. (Tightwad that I am, I think I may well have proposed to Android at Barnes & Noble tonight. Gack.)
But, as much reverence as I have for the printed word, there shouldn't be a middle ground between the two price-points. Discounting is a by-product of the industrial mentality--the extraction and manufacture of X is commoditized by mechanization and economies of scale (plus, not infrequently, cut-throat tactics and ruthless, brutal exploitation). Absolutely none of that applies to mastery of a topic or skill at helping others master it.
Oddly enough, I'm optimistic that the "ninety-five percent of everything is crap" principle will actually benefit the quality of instructional knowledge as a whole--particularly in my field. The creators of the bottom ninety-five percent--with no offense intended to their efforts or know-how--will not optimize to deliver value for the longer-term. The remaining five percent will. (As an example, consider what Jancis Robinson does for the constantly shifting geography of the wine world with what's basically a freemium business model.) In that scenario, the middle-grounders are caught between an overgrown jungle of free information and the carefully cultivated walled gardens of the brand-name authors on the topic.
Yes, it's a species of snobbery I'm guilty of here. But if it stops--or at least slows--the waste of trees and/or bandwidth on cut-rate mediocrity, that's the kind of snobbery I can live with.
Thoughts on computers, companies, and the equally puzzling humans who interact with them