That 13mil also covers r&d costs as well as the actual manufacturing costs. If we needed 10000+ the cost would go down
I think the spectrum between where we are now and “existentially threatened wartime economy” is nonlinear: if there’s not an existential threat, but there is instead a popular foreign war (e.g. post 9/11), the fraction of defense economic capacity that gets unlocked is very small—still pretty close to what we have now. Which is a lot, but it’s far from efficient.