[mktmkr]

I think you are overstating the case that the market will pass this saving through. In reality there is some market-clearing price for a dwelling without a parking space and there's nothing the developer can do to influence it. This is the same reason that it's actually not possible to "build affordable housing" as many people demand. Yes you can build the housing but there's nothing you can do about the price it then commands.

[clairity]

right, my skepticism was about the actual market dynamics and the forces that might compel pass-through savings via competition, not the econ 101 idealization of commodity markets.