Which end should I use the 7 day JRPass on an 8-Day Trip?

Hi all,

I am planning an 8-day trip, and am trying to figure out on which days I should use a 7-day pass. On the first day of the trip, I'll be taking the train from Narita Airport to Nagano. On the last day of the trip, I'll be taking the train from Kyoto to Narita Airport.

My questions are:

1. Which is more expensive, the Narita/Nagano trip or the Kyoto/Narita trip?
2. Is either of these trips expensive enough to warrant purchase of a 14-day pass instead of a 7-day pass?

Thank you so much for your help!