Prime members only. Amazon has the 20% Off $50+ Purchase of select Amazon Brand Items promo with the discount shown on the product page. Shipping is free. S&S discounts and coupons stack as well, when available. 

For example, the pictured 12-Pack Amazon Basics 2-Ply Paper Towels are $19.22. Add three to cart for $57.66 - 5% off with Subscribe & Save (can cancel anytime) - 20% off $50+ promo = $43.24 (or $14.41 per pack).