Also according to Wikipedia, the carbon content of steel is anywhere between .002% and 2.1%. Averaged, the carbon percentage of steel is 1.051%, though I doubt the percentage was anything approaching consistent (if anyone has better numbers for that please share).
So 1.45kg - (1.45kg * 1.051%) = 1.4347605kg of iron in the average longsword. At .004kg of iron in the average man, and assuming complete iron extraction from each corpse, forging a sword from blood-iron would have taken 358.69, or 359 dead men (far fewer than I expected, frankly).
TL;DR: at 359 humans, it’s one damn expensive sword to make.
If I ever become an evil dictator, this is the first thing I’m doing.