I have thought about it and decided that
1) I wanted the 3 volumes of the trilogy to match in both ebook and paper and that was easiest to arrange if vol 3 was packaged in D2D, just as the first 2 were.
2)I am going to maximize the benefits I get for their admin fee. I think I will be paying less than $1 per channel: I'm pretty sure my time for doing all the admin myself would cost more.
I may think differently when the time that they bill me is closer (the emails said January).
