Dead Island is going to be listed at a price point of $49.99US on the steam platform for individual players. However, there is a four-player pack available for purchase at $149.97US, which equates to $39.99US per copy, saving players a full $10US on the full price of the game.
When you Pre-purchase this game on steam, you will be given an exclusive pre-order weapon, The Ripper, which is a combination of a Chainsaw and Bat, for use within the game. Players will also be given free-access to the DLC ‘Bloodbath Arena’, which is a separate gamemode that has players taking on hordes of zombies for items and XP.
Check the STEAM page for purchasing info.