Hi there!
I made a quick list of ticket prices to see if the 7 day JR Pass would be a good option:
Yokohama - Nagoya ¥ 10,590
Nagoya - Takayama ¥ 5,670
Takayama - Kyoto ¥ 9,380
Kyoto - Kobe ¥ 1,050
Kobe - Osaka ¥ 390
Osaka - Nara (return). (¥ 780x2)= ¥ 1,560
This adds up to ¥ 28,640 the 7 day JR Pass is ¥ 28,300 or ¥ 340 in savings. Which is a nice cup of coffee. Now do remember that any additional travel you would do (perhaps to the Airport?) would also be covered by the JR Pass and you also have the flexibility to take any train you with for 7 days.
I hope this helps!
Daniel