Amazon has launched its Buy 2 Get 1 Free sale, which includes several notable videogame books such as Dragons Crown: Official Artworks, Marvels Spider-Man: The Art of the Game, NieR: Automata World Guide Volume 1, The Legend of Zelda: Art & Artifacts, Mega Man: Official Complete Works and more.
Source: N4G PC Amazon's Buy 2 Get 1 Free sale includes several notable videogame books