Even though I work, have a family and play Warcraft, I bought the Limited Edition of Forza Motorsport 3 (and then didn't play it as much as I wanted to). I admit that I'm a sucker, but I love driving games and Forza 3 is the best game of its kind (Sony fan boys can go ahead and eat their hearts out now). Anyway, I paid $80 for the Limited Edition which came with a bunch of goodies (that I don't use) and the price keeps going up.
Here's the scary part, I could spend another $15 on additional downloadable content (DLC). One more cap pack, which would normally sell for $5 will push the total price to $100, and that makes me wonder how much DLC should a publisher try to sell. It's 2010 and the world's economic foundation is circling the drain, yet we have a video game that costs almost $100. Even in better times, I would question the sanity of someone trying to sell that.
DLC has an added effect of segmenting or partitioning the online community. If 10 people buy the game and only 5 buy the first DLC pack, then there are two segments of players, over time, with more DLC, you continually segment, and eventually fracture, the community. I think the fracturing of a community is just about the worst thing you can do to the long term life of your game (other than shipping it broken).
The goal of DLC should satisfy a few goals...
I assume, that thru price sensitivity and the fracturing of the community, that you hit diminishing returns on those goals very quickly. I have bought one DLC pack so far, and if I want to play the game online and be able to participate, then I pretty much have to commit to all of the DLC and throw down more money. That has an inertial effect where I have to keep up with the Jones's and keep on buying! Well, I'm not going to keep buying, because it's 2010 and I have a credit card I need to pay off. Sorry Turn 10, I love your game, but it costs too much for me to keep going.