Amazon offers Prime members the Kamik Kids' Waterfight Rain Boots in Black or Viola for $18.96 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, it adds $5.48.) That's the lowest total price we could find by $16. They're available in Little Kid sizes 11 to 13 and 1 to 3 and Big Kid sizes 4 to 6, although not in all size/color combinations.