MiniInTheBox offers the Brelong 6.5-Foot 60-LED USB RGB Waterproof Strip Lights with Controller for $6.49 with free shipping. That's the lowest price we could find by a buck. It features combination, wave, sequential, glow, flash, slow fade, twinkle, and continuous modes.

Note: This item ships from China and may take two to five weeks to arrive. Uncheck "Add Shipping Insurance to your order" during checkout to remove the 49-cent fee.