I'll be returning to that in part three, but the land lease will either be based on ground area times attractivity (measured by population density in a log scale) or a simple auction to establish market value.
How that ground lease cost trickles onward is basically up to the market actors involved. If I signed a lease of an apartment, I imagine I would be paying a landlord who leased the ground for the building.
Great. Now, we have to patiently wait for part three.