- Welcome to the board!
I'm not sure if the fact that the art-books are from Japan would raise the value. If I remember correctly, those were also available to outside Japan through Internet, right?
But yeah, if you can get them signed by Vic and Aaron and Catlin, I'm sure that could raise some values, though I have no idea by how much. XD
You can probably post this question on Anime Con
thread, and people who post there would probably know more about those things?