I had to pay less than the price of a cheap nendoroid so it's OK I guess.
I would advise to plan in advance what you want to see. I didn't and ended up staying too long. Try to know some basic Japanese like "where is thing/place" so you can ask people on the street for direction. Knowing the kanji for the number can be useful, some restaurant have the price only listed with them.
As for the stuff to see. My favorite are miajima, which is an island near Hiroshima, it's really beautiful. I visited the castle of Himeji. It's nice from the outside but the inside is kinda meh. However near the castle there's a garden called Koukou-hen or something like that, it's really pretty, I liked it a lot.
If you're visiting Kyoto, all the temple make you pay ~500¥ entry fee so prepare the money accordingly. Visit temple that have a garden or something and it's better if they let you inside. Some have so little material it really take 20min top to visit them. For examplethe kinkakujin, which is a very famous one, they let you look at it from a distance and it's all. In Kyoto I really liked the Nijo castle and the guided tour of the imperial palace.
In term of place to see, Tokyo is a little bit below Kyoto I feel. There's temple and everything but Kyoto made me expect bigger, so to say. So keep that in mind when you're planning your trip. If you're a city person Tokyo is really for you. There's lot of things to do. If you want to go to a maid cafe, go to one whose flyer-giving maid invited you, they have English speaking staff and you'll enjoy it more.
The JR pass is really useful, especially if you plan to travel a big distance, since you can take most of the shinkansen for free with him.
