@panpacific I agree 15% sounds questionable. Maybe I heard him/her wrong and it was 50%. 
In all seriousness, I have read overall BS are more generous than colleges, and the school of this particular FAO was reasonably well endowed. Further, 15% of HH and the dollar figure as you calculated are somewhat in alignment with this article: http://www.nytimes.com/2014/03/15/your-money/for-boarding-schools-an-evolving-financial-aid-philosophy.html?_r=0
May just be wishful thinking. From this standpoint, it seems like a guessing game but Thursday more light should be shed. Thanks for the encouragement! 