AltaTac via eBay offers the Sigma Eloy 4-LED Bicycle Headlight in Black or White for $6.99 with free shipping. That's a buck under our June mention and the lowest total price we've seen. (It's a current low by $5.) Features include permanent mode operation with up to 100 hours burn time, flashing mode operation with up to 200 hours burn time, side visibility, water resistance, and a tool-free battery compartment. It mounts to most 22-32mm handlebars.