Osaka-Kyoto-Nara-Tokyo

Hi! I'm planning a trip to Japan this November. And we're planning to tour around Osaka for 2 days, then day trips to Kyoto and Nara and then transfer to Tokyo. Will it be more cost efficient to get the JR Pass 7 days? If it wouldn't be too much of a hassle... a cost comparison can be very helpful.

And will I still be able to use my JR Pass on local trains in the mentioned cities?

Thank you very much! Still getting dizzy with all the details of preparing the trip :)