Myprotein offers its Myprotein Impact Whey Protein 5.5-lb. Pouch in several flavors starting at $39.89. Add three to your cart, then apply coupon code “JAN18” to cut it to $72.99. (The coupon yields the same price even for more expensive flavors.) With free shipping, that’s $92 off and the lowest price we could find. It has 100 calories and 19g of protein per serving.