premise: If you've ever wondered why saffron is so expensive, it's because 150,000 of these purple or white crocuses (only the stamen is orange) are necessary to make up a single kilogram (2 pounds) of saffron proper, the stuff that flavors and colors those famous Indian curries and Spanish paella.
hypothesis: Saffron is expensive because the materials needed to make the materials are expensive and the end result is small.