It’s true that decades ago, master perfumers tinkered with ingredients that were harder to source. Natural ingredients reigned supreme, some of which were very expensive, like iris root, rose de Grasse, jasmine, and oud. Certain notes came from sources that were allergenic, environmentally harmful to harvest, or collected from animals using cruel methods, so necessary changes were made to use more and more synthetic ingredients. As a result, many perfume houses were able to cut the costs of production with inexpensive, great-smelling, and abundant man-made molecules. They did not—and still have not—passed those savings on to the consumer. To their credit, the dupe brands are.

—Read more in Why Is the Fragrance Industry So Obsessed With Secrets? at Harper's Bazaar.