I think most people here are missing the end game ramifications of this pricing scheme. They seem to be taking the same approach oil/gas merchants are taking. While gaming isn't a necessity like gas/oil is, the same logic applies.
They will gradually force prices up and up. They doubled the price in this instance, but its probably more or less to test the waters. For every person here saying they would never pay these prices for games, there are probably anywhere between 2 and 5 people who would, and will. Thus giving Microsoft or any other digital distribution service provider the go ahead to keep spiking prices.
Gaming prices have steadily increased over the past decade, and it isn't going to slow down. So far it has been claimed to be for rising development costs, but it would take an idiot to overlook the fact its all profit motivated.
I prefer steam over any other distribution method, and have over 50 games from them, but I'm not blind as to the failure of steam to live up to the initial promises of lower costs due to brick and mortar or physical materials being eliminated from the equation. Outside of the random and planned sales events, Steam pricing isn't as great as everyone makes it out to be. However it still does knock the pants off just about every other digital distribution.
Long and short of it is this, get used to it. Our hobby has gone mainstream and corporations, publishers, and retailers will suck every penny out of it no matter how unpopular, ridiculous, or outright unethical it might be.