For the price of the Iraq War, we could've bought a cauldron and a broom for every woman born since the writing of the Malleus Maleficarum, or "Hammer of the Witches", a 15th century witch-hunting guide.
Written in 1486, the Malleus Maleficarum argued that witches existed, claimed that women were more likely to commit witchcraft, and advised authorities on how to detect and convict witches. It spread rapidly throughout Europe, leading to the deaths of tens of thousands of people through witch trials. Even today, some right-wing activists like Catholic League president Bill Donahue profess a belief in witchcraft.
Extrapolating from calculations by the Population Reference Bureau suggests that 12 billion women have been born since 1486. A 10 quart cast iron cauldron from a witchcraft supply store costs $150, while a broom costs $5. Buying these items for every woman born since 1486 would cost $1.86 billion, or $1.14 billion less than Joseph Stiglitz and Linda Bilmes' estimate of $3 trillion for the total cost of the Iraq War.