[sobellian]

- Source for Vulcan total program cost? All I can find is their per-launch pricing. Tory Bruno himself apparently said that "new rockets typically cost US$2 billion, including US$1 billion for the main engine."

- Not sure where you're getting the SLS number, the GAO report at https://www.gao.gov/assets/gao-23-105609.pdf claims, "Since 2011, NASA has spent $11.8 billion to develop the initial SLS capability."

- I think the marginal cost is a fair question. The whole party line out of NASA was that this time Moon exploration would be sustainable. If each trip costs > $1B before you even put a payload on the rocket that's a big problem.

[pclmulqdq]

I completely agree with you on marginal cost, but I don't believe SpaceX to provide accurate numbers for their own rockets before they are actually built (they love wishful thinking) or their competitors' (making your competitors look bad is better for you).

[sobellian]

Okay well respectfully I looked at the number you provided for the closest comparison rocket, SLS, and it was 6x too charitable.