In the picture you see regular plumes against the "mutant plumes". Where the regular plumes run about 18 inches long, about 6 or 7 inches wide, mutant plumes average 24 inches long and about 10 inches wide. One of these in your hat looks like 3 regular sized plumes. I like to take a few of these, and a couple of the smaller ones, arrange just so, then zip-tie them together to put in my hat, creating a huge cascade of feathers.  You are ordering by single plumes.  It takes about 6-8 plumes to achieve the effect you see in the photo.