It's a little of everything price for the technology in such a limited run and the R&D costs as well as price margins. The the reason why Elon Musk decided to make the Starship out of stainless steel vs carbon fiber or some other more complex material is because of keeping costs down. They even recently did a complete redesign of the fuel tank because it had a cone head and decided to make it flathead in doing so they cut the number of stainless steel sheets used by more then half bringing the costs down even more. The Starship costs per flight currently around 500 to 1 billion with the eventual goal of getting it down to 20 million to 2 million in a perfect world per flight. This is a rocket with a 120 ton payload capacity for best case 2 million a launch crazy.
VS 4 billion per launch for the SLS lol.
"NASA has been working on the Space Launch System (
SLS) since it retired the Space Shuttle in 2011. The agency initially hoped to have the mega-rocket flying by 2016, but that proved to be a wildly optimistic estimate. As the delays piled up, so has the cost. In a recent House Science Committee hearing, NASA Inspector General Paul Martin revealed the true cost of an SLS launch, and it’s much higher than the $2 billion target. It’s more like $4.1 billion, but Martin turned things around on the Representatives, reminding them it was Congress that dictated the terms of NASA’s SLS contracts. "