"It cost about 75 cents to kill a man in Ceasar's time. The price rose to about $3,000 per man during the Napoleonic wars; to $5,000 in the American Civil War; and then to $21,000 per man in World War I. Estimates for the future wars indicate that it may cost the warring countries not less than $50,000 for each man killed."

Source: Source: interviewingauthors.com