Thank you for the reminder, deadpixel.
I'm ok with not getting the final dragon in this event - it isn't my favorite, and space is at a premium. However, if I had really liked the dragon, I would have been disappointed.
I have done some thinking recently about the importance of activating the second den and realized that it is important most of the time, but sometimes I try to save just a smidgen of money by skipping a week.