Amazon has the 10.58oz Optimum Nutrition Gold Standard Pre Workout with Creatine, Beta-Alanine, and Caffeine (Green Apple Flavor, 30 Servings) on sale for $17.15 - 5% off with Subscribe & Save (can cancel anytime) = $16.29 with free shipping on $25+ or with Prime. Roughly $1.54 per ounce.

In addition, the Blueberry Lemonade flavor is on sale for slightly more after S&S. Roughly $1.55 per ounce.