DLC shouldn't be charged for at all whether or not it is already on the disc. Take the time to make a complete expansion or release extra content for free. Tons of PC games got free DLC before this gen made developers realize how incredibly dumb their customers are. You are paying $5-10 for something that takes them like 1% of the effort that making the game itself took.
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Starcraft is my life, so without it I wouldn't exist. - Artosis
Congratulations to SuperNiceDog for winning the 2011 Guru contest.