Amazon offers its Prime members the Maxsa Innovations Battery-Powered Motion-Activated LED Light in Dark Bronze, model no. 40342, for $6.66 with free shipping. (Non-Prime members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $5.58.) Aside from the mention below, that's the lowest total price we could find by $3. It features three LEDs and can detect motion up to 10 feet away.

A close price: Walmart sells this light for $7.44 with in-store pickup via Site-to-Store.