Charles River Editors has a handful (maybe as many as 10) of
free books that seem not to be repeats. Unfortunately, they are intermixed with repeats.
Here's
a link of the ebooks, sorted low to high. The first one, for some reason, is actually not a CRE book (however, it is free, and you might enjoy it--it's a 40-page booklet with a Christmas story by Lyman Frank Baum, of
The Wizard of Oz fame). Once you get down the list to the Adam Smith ebook on the
Wealth of Nations, then the ebooks cost you money.