Musk talks about how there's no one area where costs were reduced in space travel, rather it was every decision across the board. The focus was on simplicity--and simplicity reduces costs. For example, fewer components means fewer components to repair, and to purchase, as well as to test. The avionics vehicles communicate via ethernet--while not novel, it is unheard of, compared to other systems that use cables, he says. In addition, overhead at a 30 person company is much cheaper than at Lockheed or Boeing, he notes.