As I’m sure you know, Tokyo is a really big city. How big is it? You can see the subway map here:
http://www.tokyometro.jp/rosen/rosenzu/pdf/rosen_eng.pdf
I’ve not ever counted how many lines and stations there are in Tokyo, and also, there are many railways. You can guess how big Tokyo is now.
If you move to Tokyo, you may wonder where you should live. Of course, it depends on your situation; work, school, etc.
Usually, the west side of Tokyo is a more expensive area than the east side, apartment fee, food at supermarkets and so on. In the same way, north is cheaper and south is expensive.
How about the centre? You can find apartments or house there but mostly it’s a business area, not suitable for daily living. Far from the shops, far from the supermarket, you can find only small grocery stores and even then it’s weekdays only.
As for the apartment fees, it depends on the station and how long it takes from station to the apartment. Usually if you walk 1 min. more from the station, you can get an apartment 80US$ cheaper.
If the express stops at the nearest station to your apartment, that area must be expensive.
Now, you may consider it prudent to live a little bit towards the outskirts of Tokyo but I have to tell you if you live in that area it takes one and a half hours from the centre of Tokyo, and you’d end up taking a bus or walking for 20min from the local station to your apartment.
Of course, if you don’t mind the possibility of living without shower room, share the toilet with neighbours, live in a very old building or only have one tiny room, you can live cheaply in Tokyo.
Where would you live in Tokyo?