I've noticed for some time that real estate is cheap
east of Chiba city, about the same as rural areas here,
yet within a 50 km radius of Tokyo.

Is there a particularly bad reason for the area to be
cheap? In Kujikiri, I would be a 6 km, 25 minute bus
ride from the station, but I could be walking distance
from the beach, on hundreds of square meters of grassy
residential land.