The big issues that consistently affects real-estate around Tokyo is proximity to a station and the age of the building. The basic rule is that a condominium must be within 10 minutes walk from a station, and a free standing house up to 15 minutes walk. A house around 30 years old is worthless, and a house younger will be some fraction of its original purchase price. There are exceptions but this is a pretty good rule of thumb. Land is generally the only thing that appreciates in value and only if its in a desirable location. As a point of reference, we live in an 90m^2 home 45min from Tokyo station and it was less then the above price.