SheIn offers its SheIn Women's Floral Cut Out Cami Dress in Yellow or White for $18.99 with free shipping. That's $11 off list and the lowest total price we could find. It's available in sizes S to L, although not in all size/color combinations.
Note: Uncheck "Add Shipping Insurance to your order" during checkout to remove the 99-cent fee.
Note that new customers can apply coupon code "SHE4" to cut the price further to $17.99.