In regards to formatting $, Vellum, Vellum, Vellum. You'll never go back.
Vellum is very reasonably priced for what it does.
For me the biggest advantage is the paperback formatting. I could never get it done in less than a day or two. Vellum does it in seconds--and better than I could have done it in a day.
I should note that I haven't tried D2D's free formatting options. That might be an acceptable substitute, especially if you're a PC user and/or are on a really tight budget. (I'm a PC user but have an old Mac laptop that can run Vellum.)
