JR Pass Need Check

Dear Alexis,

From 6th-25th March we will be in Japan, landing in Narita. The trip will be as follow:

• Tokyo (6th-11th), with daily trips to Nikko and maybe Hakone
• Osaka (12th-16th), with daily trips to Nara and Kobe
• Hiroshima (17th-18th)
• Kyoto (19th-22nd)
• Tokyo (23rd-25th)

I have checked the JR Pass and realized that the 3 weeks option is much less convenient vs. buying single Shinkansen tickets. This said, only IF the Shinkansen prices do not increase over time, and also IF the tickets are available with short notice (same day). Can you please confirm these two points?

Finally, do you think it would make sense to buy the JR Pass for 1 week, and activate it on the 12th when traveling from Tokyo to Osaka? Then we would use it until and including our trip from Hiroshima to Kyoto on the 19th. All the train tickets before the 12th and after the 19th will have to be bought separately. Would this option make us save any money?

When checking the single ticket Shinkansen prices online, it does not seem like the JR Pass is so convenient... Unless of some heavy travelling, it seems to me that buying each Shinkansen ticket is in fact more convenient vs. making the JR Pass subscription. Not sure if I am missing something here...

Thanks in advance for your reply!
E