The holiday buildings are always cheap. They set them that way so that people who just started playing the game can buy them. It's the same reason that whenever we are able to do special tasks for the holiday, it will be characters like Homer, Lisa, Flanders, or Apu. Those are all the people you get very early in the game.
mrags, what type of phone are you on? I had to download an update through the iTunes store before the game could update.