It's cute how people defend shitty money-grubbing tactics with "hey companies need to make money too!"
It's kinda like a gas station in the middle of the desert charging $20 to use the restroom. If you really don't want to take a shit behind a cactus you'll pay up, but you sure as hell aren't going to buy anything else from them in the future.
Likewise, selling a recycled map pack for $15 that the companies know you'll buy so you can keep playing with your stupid friends, is shitty. How can a recycled map pack ever be worth 1/2 of what I paid for the original game? Its price will also never go down, and I can't even resell it when I'm done with it. Most gamers have contempt for companies like Activision and EA for these kinds of things.
I think all people are asking for is fair pricing. If a sp DLC is going to be $10 it needs to last longer than 30 minutes, two new maps should never be more than $5, etc. The companies could even make more money in the long run because more people would be inclined to buy it.