Compared to past years, we are saving around $500 a month on our heat bill during the winter months. When we did the project last winter, I stated in my posts that these types of projects would be worth the cost because of future energy savings. One comment I heard was "That's good and all, but how long is the payback period and is it worth the time and expense?" The payback period was 1 year. I can't wait to see the low heating bills on a "normal" winter.
See my "Rainy day project" post from November 2012 under the Maintenance Building label.