SpaceX has been a huge advantage to the US taxpayer.
SpaceX costs are lower
The ULA monopoly ended when SpaceX began to compete for national security payloads alongside ULA, and launch them. (The California-based company's first national security launch, a National Reconnaissance Office spy satellite,
came in May). And side-by-side the government's estimates for ULA launches, SpaceX's costs appear to be considerably lower.
For example, about 14 months ago, the Air Force awarded SpaceX an
$83 million contract to launch a GPS 3 satellite. And in March 2017, SpaceX won a contract to launch another GPS 3 satellite for
$96.5 million. These represent "all-in, fully burdened costs" to the government, and so they seem to be roughly comparable to the $422 million "unit cost" in the Air Force budget for 2020.
FURTHER READING
Citing costs, US Air Force turns to SpaceX for its next spy plane launch
SpaceX sells basic commercial launches of its Falcon 9 rocket for about $65 million. But, for military launches, there are additional range costs and service contracts that add tens of millions of dollars to the total price. It therefore seems possible that SpaceX is taking a loss or launching at little or no profit to undercut its rival and gain market share in the high-volume military launch market.
Spoiler alert: It’s a lot.
arstechnica.com