The Craft sequence by Max Gladstone is on sale for $4.99 in the U.S at
Kobo and
Amazon.
I assume this is in preparation for the release of the next book in the series in 2 months. According to his
website the promotion's been running since May 18th so I don't know how long the prices will stay this low.
I really enjoyed the "first three" (they are published out of chronological order) books of the series, haven't read the fourth yet.
Its a Urban Fantasy series but not set in the modern world but rather a fantasy setting where the people in the new world (the Americas) overthrew the gods to use their power for themselves with the help of the Craft, magic powered by what amounts to business contracts.
Each book tells a complete story that stands pretty well on its own and features different main protagonists, but characters from earlier books turn up in the later books and events are mentioned.
Edit: For those interested. The books are published by Tor and therefor provided DRM free.