Argan oil can cost as much as $300 per liter. Why is it so expensive?

Argan oil can cost as much as $300 per liter, making it the world’s most expensive edible oil. Just 20 years ago, however, the production of argan oil was isolated to villagers in Morocco, who sold it locally for as little at $3 per liter. But since then, the formation of women-run cooperatives has transformed the production into a billion-dollar industry. With the help of the cooperatives, the traditional skills held by the Amazigh women has created some financial independence in a male-dominated society However, the women normally make less than $220 a month — below Morocco's recommended national minimum wage. So why has argan oil suddenly gained such popularity? And what makes it so expensive?