I also feel justified in taking these "expensive pictures" because it was mentioned by President Thomas S. Monson in the October 2008 General Conference. He stated in his talk, "Brother Hess wrote—and I quote: “These things are important: temple marriage, mission, college. Press on, set goals, write history, take pictures twice a year."
So, there you have it. I'm now justified in taking pictures of our kids. Now, we just have to work on getting those family pictures taken a little bit more often.