http://vgchartz.com/games/game.php?id=1112
A game that sold under a million on the PS2 is going to break 2 million on a system with less than 1/10th the install base? The reviews have it pegged as average at best as well. If a game like Ratchet and Clank suffers from lowered sales due to lower install base, then Killzone 2 is certainly going to suffer as well.