Today through Sunday, Chronicles of M - Book 1 is free. Books 2, 3 and the Trilogy set are still the standard price. If you pick up the first book and want the rest, I'd suggest either clicking the links in the first book, or searching for my full name (Nicholas Forristal). For some reason if you type in "Chronicles of M" book 3 and the trilogy set do not come up. No clue why, as they are labeled like book 1 and 2.
By the way, if you didn't know the trilogy set is slightly cheaper than buying the books separately and it comes with some bonus content. At the least, here's the links for Book 1 on amazon in your area.