Under $150, this long black prom dress is a beautiful style that proves that you don't have to spend a fortune to look wonderful. Cold-shoulder dresses are trending for prom 2018, and this style boasts a unique take on the style with a deep sweetheart neckline and banded sleeves on the empire-waist bodice. The fitted long skirt hugs the curves and has a ruched back and sultry side slit. Figure-flattering as a military-ball dress or winter formal dress, this long black prom dress by Emerald Sundae is a classy style that won't bust the budget.