The answer largely depends on which schools you are planning on applying to. However, with a low-end GPA I would advise re-taking. But then you must ask yourself whether you can recreate your high scores in other sections.
Also, keep in mind that some schools have minimum requirements for all sections (Ex. UCSF needs min 17 on everything). Which goes back to my first sentence.
good luck.
P.S. You may also find it useful calling the schools to which you are applying and asking the same question.