“A holy grail lotion.” Serious skin care doesn’t have to cost serious prices. Case in point: Rosen Apothecary’s anti-aging retinol body lotion designed to smooth and brighten skin — for under $20. This “ Holy Grail of lotion ” is currently 28% off, making it under $18, the lowest price it’s been since May. Reviewers love how soft and light the cream is, saying it glides on “ like water, ” absorbs quickly and offers a light mango scent that’s perfect for summer. Though, it’s mainly loved for how