A lot of people are commenting (correctly) that any cost savings achieved here are trivial relative to the land cost. I think this is looking at this tech too narrowly though. There are many areas of architecture that can be revolutionized by cheap, accurate mass-customization.
One example would be energy. Right now heat transfer and the transmission of daylight through walls/windows can be theoretically optimized to reduce energy costs simply by customizing the geometry of the windows and walls relative to their orientation and local context. We don't do so in architecture because the costs of customizing the geometry is too expensive. Architecture has a history of attempting mass-customization since the 1960s[1], but it's always been limited by the technology and realities of integrating multiple subcontractors and consultants. Those problems still exist, but the industry is changing pretty fast and I feel automated form generation, simulation, optimization, and production technologies are converging to a point when this could be achieved.
One example would be energy. Right now heat transfer and the transmission of daylight through walls/windows can be theoretically optimized to reduce energy costs simply by customizing the geometry of the windows and walls relative to their orientation and local context. We don't do so in architecture because the costs of customizing the geometry is too expensive. Architecture has a history of attempting mass-customization since the 1960s[1], but it's always been limited by the technology and realities of integrating multiple subcontractors and consultants. Those problems still exist, but the industry is changing pretty fast and I feel automated form generation, simulation, optimization, and production technologies are converging to a point when this could be achieved.
[1] i.e John Habraken.