Amazon offers the Ortho 2-lb. Snake B Gon Snake Repellent Granules for $8.48. Clip the 20% off coupon to drop it to $6.78. Plus, check out via Subscribe & Save to bag free shipping. That's the lowest price we could find by $3. It's designed to be used every 30 days as needed and has a no-stink formula.
Be sure to cancel your subscription after receiving your item to avoid being billed for subsequent shipments.