In addition to their $0.25 daily deals, Google is offering 100 Books for $3.99 or Less
in the US. Also advertized on the store's front page as "100 Great Reads". They are a good cross section of non-Agency titles, some with a significant discount. With more non-fiction than the typical discount list. Amazon is matching Google's prices.
Google provides an Adobe DRMed ePub download option. If you get a sample instead of the entire ebook, see OddCosine's Post
on how to fix this.