Nordstrom Rack cuts up to 89% off a selection of women's dresses, with prices starting from $11$12.08. Shipping adds $7.95 or get free shipping on orders of $100 or more. Sizes may be limited. A couple of best bets:
Revolve offers the Jack by BB Dakota Women's Harmonica Sequin Dress in Multi for $20. Coupon code "CANDY" cuts it to $18. With free shipping, that's the lowest total price we could find for this dress in sufficient stock by $57. It's available in sizes XS and S.
Note that this item is final sale and cannot be returned or exchanged.