Walmart offers the Bird-X Irri-Tape Bird Repeller 100-Foot Ribbon for $8.43. Choose in-store pickup to dodge the $5.99 shipping fee. (Amazon charges the same price with free shipping via Prime or Subscribe & Save; Home Depot charges the same via pickup.) That's the lowest price we could find by $21. It repels birds with 3D shapes and colors, and covers up to 4,000 square feet.