ULA is triple the cost of SpaceX and they have an $800 million rider with the DOD for "at moments notice" launch. That makes them almost quadruple the price SpaceX. [1]
[1]https://arstechnica.com/science/2016/03/ula-executive-admits...
My point is that there are other methods of assurance; one of them is additional investment in reliability, something SpaceX is trying to avoid.
> ULA is triple the cost of SpaceX ...
Perhaps that's how much sufficient reliability costs. In much of engineering, and at least in IT, high-reliability is one of the most expensive requirements. As a simple example, compare the cost of an unreliable consumer ISP service ($30/month for maybe 15 Mbps?) and a reliable T1 circuit ($300/month for maybe 1.4 Mbps?) - you pay 10x for 1/10th the speed.
From my seat in the bleachers, it will be interesting to see if SpaceX can deliver high reliability for significantly less than ULA. Good for them and for everyone if they pull it off.