SheIn offers its SheIn Women's Spaghetti Strap Hollow Lace Dress in Black or White for $17 with free shipping. That's $9 off list and the best deal we could find. It's available in sizes S to XL.
Note: Uncheck "Add Shipping Insurance to your order" during checkout to remove the 99 cent fee. This item ships from mainland China and should arrive in three to four weeks.