Have you seen the IAC presentation Musk gave? Incredible.
The actual BFR is going to be scaled down, but still more powerful than the Saturn V, and 100% reusable. They are also looking to use it for suborbital commercial passenger flights.
https://www.youtube.com/watch?v=AxjGKm5-1eM&feature=youtu.be
It took something like 40 launches to build the ISS. Using BFR and Bigelo Aerospace’s largest modules, it would only take two launches to build another space station of equal inside volume.