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Honestly they should make the dlc a lot cheaper for those who are playing the original package but releasing a game with the dlc in box later down the road is a good move.
In my opinion that's a good way to handle things. Sure it will be more expensive in the long run for people who bough the game on day one but it also makes it much easier for new people to jump in.
In what way did they handle the DLC differently to any other game?