120,000 were previously killed by God and Gideon. (8:10)
According to this verse, Gideon and his God-picked army of 300 water-lappers slaughtered 120,000 Midianites (with only Midianite 15,000 survivors). And yet all of the male Midianites were supposedly killed in Numbers 31, which would have been only a couple hundred years before this.
1700 shekels (8:26)
Since a shekel weighed about 11 grams, this would be about 18.7 kilograms of gold, worth about 1.2 million U.S. dollars today.