What Makes Saffron Such An Expensive Spice?

Saffron is the most expensive spice in the world.
It is used in a variety of cuisines, as well as a fabric and skin dye.
And just one pound of the spice can cost consumers $5,000
But just what makes saffron so wildly expensive?
It's a complicated spice to harvest, requiring a lot of physical labor.
Saffron comes from the saffron crocus flower, which has three red stigmas.
The stigma is the female part of flower, which contains the saffron spice.