Just curious but does anyone have an idea on the price of manga in Kyoto?

I need your opinions on an upcoming Japan trip of mine.

I've booked my plane ticket to Osaka for next year February and will be in Japan for 16 days. I'm currently planning my itinerary and am not certain if I should plan the entire trip around the areas of Osaka, Kyoto & Nagoya or should I extend a few days to Tokyo (being a major city that people always go to).

I'm certain I will be visiting Japan again in the future so I'm in no rush to see everything in this one trip, but I'm not sure if there'll be enough activities to fit into my itinerary if I limit myself to a few areas only.

So your opinions would be greatly appreciated in this. Thanks in advance guys. :)