Now it's been 14 years since I've had my prom, but I do recollect it being quite pricey. Dresses on average cost anywhere from $125-$500 and sometimes girls miss out because they can't afford the experience. Saturday June 3rd Six Flags will be collecting formal gowns for the organization Princess & the Prom. Dresses should be in like new condition for the 2018 Prom Season. Last year they collected 350 formal dresses for girls in need. They will also be collecting jewelry and shoes too, but to get free entry into the park tomorrow you must donate a formal gown. - Maybe you can take a ride on the new JOKER!