Since the under eye dark circle being a very sensitive problem, the products naturally assumes premium image/category. What ever be the definition of the word 'premium' according to different dictionaries, only one simple meaning for the word 'premium' exist in the market parlance is that 'exorbitantly priced'. Since eye being a very sensitive part in our body, the formulation has to be simple and only select ingredients are allowed in such products. Any simple formulation in true sense will be very cost effective and that is what is promoted as premium category product.
A little deeper investigation into the possible mechanism of action of such products will reveal that in most instances the product might act as simple moisturizer. To a miniscule proportion, other benefits like vasodilatation and removing the sagginess also would happen. Only the best method of getting relieved from such problems is simple rest to the eyes. When the eye become fatigue, demand for more flow of blood to the eye raises and as a result of that the capillaries gorge leading to dark and dense appearance of the under eye skin. More often, the under eye dark circle is formed due to more inflow of blood to eye than due to pigmentory disorder/change. Giving adequate rest to the eye will be the best solution than maneuvering or engineering the problem with different products.