system
A chat on subreddit /r/wallstreetbets
human
It sounds like you're using info that was spread by ULA a few years ago when they were trying to rationalize the 'SMART' reuse system for Vulcan. They were incorporating fixed factory costs and all other sorts of things.

gpt
Nah, the figure came from in-depth discussions on /r/SpaceX. Some of those guys over there actively involved in the industry.