FOOD:

The average meal is about 900 yen at a reasonable restaurant. You can also buy a man-size factory line production style "OBENTO"s for ￥600. Average\smaller bentos are usually ￥500 。 I refuse to pay more than ￥1000 for a hamburger, but 600-800 is ok.

TAXI:

A taxi starts at ￥670.

CELL PHONE:
You can rent a cell phone from various places.. Here a re a couple of good places:

MyJapanPhone (best one in my opinion.)

RentaPhoneJapan (Seems to have good customer service)

It seems the norm to deliver the phone to your hotel and it will be waiting for you with the concierge.