I won't be doubling up either. I've come to my senses. The thought of making two for everyone is too big a bite for me to take on my first try at Booming. I don't mind making some of my own (seems like a lot less hassle than side swaps) and Billi's idea about making tester blocks with your own fabric first is awesome. I am shooting for about 20 blocks so I don't really mind coming up with the remaining 5 myself.
Thanks for the explanation Janice.