Huh, I looked at "On Intelligence" by Sandra Blakeslee & Jeff Hawkins, which is $19 as a DRM'ed to hell ebook, $16.50 new on Amazon as hardcover and $10.20 as paperback! How come, when going from hard to soft cover saves you 10 bucks off the list price, while an ebook (highly restricted too) is a bargain at 6 bucks off? Also, a used paperback is from $5, and that one I can even read out loud...
Not to say the least of "secure" formats - I'm not going to let anyone secure me from my content, just to go a ilttle Richard Stallman in here. :-)