Check out a business hotel such as APA or Toyoko Inn. I managed to stay in Asakusa,Tokyo for around 6000 yen last Nov.

Here's a good site for finding cheap accommodations :
[Rakuten Travel] Japan's Hotel and inn reservation site

Enjoy your trip! :)

Thanks!

I just booked K's House Hostel in Asakusa. Just for 3 nights. I just want to see what it is like in a Hostel.

The 6 nights I will find a nicer hotel to stay in. Time to find a hotel.