Most Seth Godin books could be one sentence long.
In fact, most books could be blog posts. So, if you're going to publish a real paper-based book these days, do me a favor: get to the point, charge a fair price and help me learn something. I'll throw my money at you faster than you can catch it.
There are very few books that can justify their length these days. I picked up the very small book Free Will at the library along with some others of the same size and reaffirmed my love for small books.
If I like them, I pay the $9.95 or $14.95. That's more than fair. I learn something and the author/publisher makes a nice profit. These books are cheap to make, even for small runs. I've priced it myself.
What's not a good deal, for the reader, is the typical publishing model:
400-pages of redundant back up for simple argument.
Paying $29.95 to work for the author, sifting for meaning and editing in head.
Giving up hours of my time, so the publisher has a product that has more "heft" on a shelf that doesn't exist anymore where I shop for books.
These days, I'm far more likely to pay for a small book and skim a big book. It's a lesson I'm noting for my next publishing adventure.