YMing US via Amazon offers Prime members the YMing Rotating LED Christmas Projector Lights in Red/Green or Blue/Warm White for $15.99 with free shipping. That's the lowest price we could find by $6. The set includes six lights (three of each color), features a projecting distance of 9 to 20 feet, and can cover an area of 80 to 400 square feet. Deal ends December 31.

Update: It's now dropped to $9.99.