Far beyond of caviar and truffles, saffron is the most expensive food on earth. Well, the reason comes from what and how saffron is produced.
Saffron threads are the stamens of the crocus, a delicate flower whose climate sensitivity is as its petal’s fragility. This one week blooming flower produces three stamens in average. These stamens must be attentively picked by hand and dried in a precisely set circumstances.
For just a single gram of saffron, substantial professionally paid labor needs to harvest 150 flowers. There are some less expensive varieties, but natural saffron base price anyhow is high.
Fortunately, a little saffron serves a long way and a tiny amount (fraction of a gram) of that is needed in recipes.