That best-seller for the price of $12 is based on thousands of copies, many times printed in china and shipped by container loads. There's no way you can make it for a few dollars more for short run and survive the business.

>it's not hard, or all that capital- or even labor-intensive.

Yes its not difficult but if it is not capital intensive, it will most certainly be labor intensive. Printed through a digital copier, collated, perfect bound and trimmed in one process is not the issue. Having it done "ultra cheap one-off" is and any printer small or large will tell you the same.

The idea seems simple but no one is willing to do this for free or at a loss.