Re: costs less to fly the same weight on BFR than Falcon 9
Actually Musk's claim was that it will cost less to launch a BFR than a Falcon 1. The first time I heard that I thought "What the Falcon?", stepped the video back and listened to it again. Not lower launch cost per kilo to orbit, simply lower total launch cost. I did a quick web search for Falcon 1, chose the most expensive launch and added a bit for inflation. Musk is aiming for a BFR launch cost under $10M. Over the next few days I saw other comments showing people were just as shocked as I was. It was not a mistake. Elon did not forget to say "per kilo".
If things go according to plan, you can put your falcon 9 payload in a BFR, add a Tesla Semi full of batteries for ballast, save $50M on launch costs and you get the Tesla Semi (with cargo) back on Earth. BFR will not be short of missions.