From a business standpoint, this price point is silly. I thought the whole idea was to attract the impulse buyers who might not buy the full product. At this price, they won't make any more money and they won't sell any more copies of the full product. Hell, it might even discourage people who would have otherwise bought the full game. I just don't see the point of doing this if they're not going to profit.
If the point of Case Zero is to sell more of the final game, then I think they should have just gone with a free demo. Nonetheless, I'll buy it as I want Dead Rising 2 asap.