Now I'm really curious what the cost of a modern U.S. soldier is. Recruitment and acquisition, training, outfitting, salary, food, etc. And if you build a tank once then you can park it in a warehouse nearly in perpetuity, whereas I expect humans require much more upkeep to retain skills and replace from turnover.

I'm guessing the total lifetime cost of a trained soldier is less than $8.9M but I wouldn't be suprised to find that the figures are comparable in the end.