With orders of $25 or more, Amazon offers Prime members the Dorcy Waterproof Floating LED Flashlight in Yellow, model no. 41-2510, for $3.18 with free shipping. (Non-members can spend $35 to qualify for free shipping.) That's the lowest price we could find by $3, outside of the mention below. This 55-lumen flashlight features four 5mm LED bulbs and a built-in tail cap carabineer clip.
A close price: Walmart sells it for a buck more via in-store pickup.