Unless it brought your whole score down dramatically I wouldn't worry about it anyway. Schools realize that if you score high in writing and vocabulary a low reading score is BS. Same goes if you have high scores in bio and math and a good grade in chemistry, a low chem score will get overlooked.
So unless you are borderline in a number of areas and this one subject just tipped the scales, its not worth the time or money. I've not once heard of someone's score being changed because it was manually graded. Not that it hasn't happened, but I'm sure it is exceedingly rare.