Dance the night away in this sequin prom dress that sparkles from the strapless neckline to the floor-length hemline. Featuring subtle ruching that hides the side zipper closure and provides a figure-flattering silhouette, this tight prom dress is sure to wow. With a straight neckline, allover sequins, and a side leg slit, this on-trend design is simple yet beautiful.. This long sparkly prom dress under $100 is as glamorous as it is affordable and would be the perfect choice for your next prom or formal.