Not only does calories burn differ from person to person it can also differ for yourself for day to day or week to week. Some weeks are our best weeks, such as the week right before your period. This is "your" workout week and you should focus on tackling the most difficult workouts or giving 100% and then some to your workouts.
If you ever noticed that one week out of the month you are more energtic when it comes to your workout than others it is because your hormones are off balance and in your favor as far as the workout is concerned and those calories will burn!
For BM2 I normally will burn about 750-900 depending on the week or how I feel. I wear a heart monitor watch that keeps track of calories burned, and only a few times for this workout I have hit the 900 mark, but usually stay within 750-800.
The information about "your" week I read in Women's Health and Fitness magazine, and also aksed my OB/GYN once I read those articles to confirm or deni, which was confirmed.