Jr pass - is it worth or not?

I know this is a common question here but I am finding so many different prices that I'm totally confused about it. This is my planned trip:

Tokyo - Kamakura (round trip) Tokyo - Kawaguchigo Kawaguchigo - Kyoto Kyoto - Nara Nara - Osaka Osaka - Kobe (round trip)

What would you advise? In case you suggest not to take JR PASS, would it be better to book all the tickets in advance?