It really depends on several factors such as packaging, labeling, and ingredients. Volume also comes into play as it does with most things.
SP Energy Drink is an expensive product to make because they use a glass bottle, a wrap label, and pure cane sugar. Compare that to an 8 ounce can with no added label cost and high fructose corn syrup and you have a product that cost half as much to manufacture.
The top brands are manufactured for less than 6 dollars a case.
Well, the top brand uses actual glucose and sucrose and not HFCS and is imported from Austria where it is still manufactured to this day. That adds significantly to the cost.
A container which holds an energy drink costs between 19 cents for a 12 oz glass bottle delivered, 12 cents for a 12 fl oz. can without the pull tab lid, 16 cents for the 8 fl. oz. can (like Red Bull) or 22 cents for a 20 oz PET bottle with a closure. Deco on a sleve label is about 8 cents a color, a can depends who you have color it. On average, a total package costs about 30 cents (container, closure, deco).