Comment Re:!sales (Score 1) 111
Kindle books are almost always cheaper than the new print equivalent (used print books are cheaper).
There are many good books available on Kindle offered for free on a promotional basis. Usually these books are the first in a series. I grabbed a copy of Manifold: Time for free during a promotion and ended up buying the other two books in the series, Manifold: Space and Manifold: Origin for $6.99 each.
There are also sample chapters available for most books so you can read the book before deciding to purchase or not.