I love black & white art. For me, it's more evocative and drives more imagination that most full color images. [and maybe I'm just crazy]
However...I'm concerned about POD (print on demand) - aka, most any books you buy from Amazon, Lulu, DriveThruRPG, etc.
In your experience, how often do images with lots of darkness and shadow come out looking good enough? I say "good enough" because its not fair or realistic to compare black ink on glossy pages from a $60 book vs. black ink on recycled paper from a $20 POD.
And there's the issue that every POD book is slightly different and these companies aren't known for their quality control.
Also, I'm not talking about b/w line drawings with clean lines as much as I'm referring to images where 25% of the frame will be filled with shadows, silhouettes, etc.