Amazon offers Prime members the Casio Unisex Illuminator Water-Resistant Digital Watch
in Blue, model no. F108WH, for $10.59
with free shipping
. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $4.48.) That's the lowest total price we could find by $2, outside the mention below. It features quartz movement, resin band, and water resistance to 330 feet.
A close price: Kmart
has it for $11.25 with free in-store pickup.