The SpaceX plan is what Nextbigfuture described in last months article "A Sky Full of Starships".

The SpaceX Starship will have six Raptor engines but will still be larger and cheaper than the external fuel tanks of the Space Shuttle. Elon Musk has a goal of building Starships for $5 million.

If the steel and salaries are half of the total cost of the rockets then the unit costs at different production levels would be:

Two Starships per month would mean $37 million per Starship
One Starship per week would mean $21 million per Starship
Two Starship per week would mean $13 million per Starship

Elon Musk has tweeted out modifications for the SpaceX Starship that will be used for moon landings.