I am now interested to take a look the documentary(Andrew Marr's) regarding megacities because of the facts you written here. Living in megacities are very costly because although I am living far from Tokyo but I stayed there for just a week and it is very different from Nagoya(my place) because there is no empty space that hasn't being used. Even the convenience store, I hardly see any parking space on each store and the parking of the house are all using elevated parking to save some space by any means. I told to myself that I cannot live in a place like Tokyo and still prefer Nagoya if I am planning to stay. Thanks mate