PacSun.com offers the O'Neill Women's Nautical Dreams Dress in Blue or Mint for $17.49 with free shipping. That's the lowest total price we could find by $13. It's available in sizes XS to L, although not in all size/color combinations.

Original: $39.50
Markdown: $24.99
Promotion: $17.49

BUY NOW: $17 Free Shipping at PacSun