It turns out that Atari has a better deal on Indigo Prophecy than Amazon.
Indigo Prophecy (PC) - $9.99 shipped
http://www.atari.com/us/games/indigo_prophecy/pc
Indigo Prophecy (Xbox) - $14.95 shipped
http://www.atari.com/us/games/indigo_prophecy/xbox
Indigo Prophecy (PS2) - $14.95 shipped
http://www.atari.com/us/games/indigo...y/playstation2