It is a common thought that Tokyo is very expensive, it may be true, but there are some tips that you should follow in order to not get a mortgage for your travel.
For a short stay, rent a jitensha (bicycle) for $10-30 a day : most train stations will be able to accommodate you. For a longer one, purchase a used one for as much under $100 as you can wangle, register it at the local police station and resell it when you leave. (Ask for help at the local tourist office or International Center.) This will save you a lot of subway, bus and taxi.
If you need to take public transportation on occasion, use the station bicycle parking lot and a good lock. Remember: subways are cheaper than trains and buses are cheaper than subways.
For a long stay, consider a homestay, arranged before you arrive. Contact the International Center of the city or town of your choice. For a short stay, do not pay for a western-style hotel (expensive), ryokan (the Japanese style inn, is a better experience but only slightly cheaper) or a business hotel (cheap but not so comfortable – see Capsule Hotel).
If you are not spoiled and feel you can share bathrooms, then you can find some Ryokans in central spots for as low as $30 per night. For example you can find Kimi Ryokan that offers English speaking staff and some Japanese atmosphere for $50 per night for a single room.
3. SLEEP IN INTERNET CAFE’ – MANGAKISSA
A good way to save for sleep in Tokyo is the internet cafè, the Mangakissa : for about a $1 per hour you will be able to enjoy an endless supply of Japanese comic books, Playstation and Xbox games and hundreds of titles of music to listen too. Actually for some of the people I know, it will cost them less to be in Tokyo than sitting in their homes in the US doing exactly the same things. In many of this cafes the drinks are for free and they sell lunch boxes. Some of them offer shower rooms and massage room with extra pay. Anyway it is a great stop even if you are not planning on a sleepover.
4. SHOP IN THE MARKETS
Tokyo may offer great deals for sleeping or eating, but unfortunately you might not find such cheap deals via the megastores around. Most brand name stores are pretty expensive and even the smaller ones, are not the best deal around.
Look around also for the “hyaku-en shoppu” or the 100-yen shops, which sells everything in about $1 (depends on the rate).