Inflation.

This is coolbert:

Courtesy the tip from W.B. and F.S. this item for your perusal. 

"Cost to Kill an Enemy Soldier"

[all cost expressed in $ USD]

"A few years ago [circa 1970's] a Dutch professor took time to calculate the cost of an enemy soldier’s death at different epochs in history. He estimated that during the reign of Julius Caesar, to kill an enemy soldier cost less than one dollar. At the time of Napoleon, it had considerably inflated—to more than $2,000. At the end of the First World War, it had multiplied several times to reach the figure of some $17,000. During the Second World War, it was about $40,000. And in Vietnam, in 1970, to kill an enemy soldier cost the United States $200,000."

Calculations with regard to cost of killing an enemy soldier during the times of Julius Caesar hard to determine?

See my prior blog entries regarding ancient times estimates:

https://militaryanalysis.blogspot.com/2019/12/crass.html

https://militaryanalysis.blogspot.com/2018/04/wealth.html

coolbert.