The old and new Dungeons & Dragons comics are available for pretty good prices at a holiday sale at DriveThruComics. There's a bunch of collections and single issues that are part of the sale.
This includes classic AD&D comics originally published by DC Comics back in the day.
As well as the newer Legends of Baldur's Gate comics written by Jim Zub.
While not 40% off, there's also sales on the IDW Hasbro comics at DriveThruComics, including G.I. Joe and Transformers stuff. Check it all out!