what's very confusing about the expensive fries is that some "flavored" fries are merely spices and yet cost dollars more. like "lemon pepper fries" for instance: lemon pepper is a bulk spice mix and certainly can't justify such a price point for the mere shaking of a can. perhaps these special fries also come with some sort of special sauce that might cost more. sauces often contain ingredients or require labor that would justify the higher cost.

also, if the sweet potato fries are made int eh same fryer as the regular fries, then the longer cooking time doesn't matter. the fryers are on and heated no matter what you put in them and they remain on until the kitchen closes. it uses no more energy to cook one thing over another. now, if these special fries are cooked in a pan or something, then that is a different story.