Part of that also comes from the pricing model. ULA has often done cost-plus contracts, which incentivize inflating the cost. When SpaceX joined the party, most of the contracts became fixed price (i.e. the government is going to pay $X, and it's up to the launch provider to build their profit into that, and any cost overruns are the provider's problem).

> SpaceX is now competing for those launches with a price between 1/4 to 1/3 of what ULA is charging.

Is there really a competition for this much price difference?