Should I retake the SAT?

I used up my two fee waivers from college board for my previous SAT attempts. On my first attempt, I got a 1350 (with studying on Khan Academy each week during class, like 90 minutes a week).

On my second and third attempt, I got a 1340, and it's mostly because of my lack of preparation. I took my second attempt near the end of May (last minute decision, so it was sort of rushed), and then just recently in August (did not prepare AT ALL during the summer, so I was pretty surprised to get a 1340 without studying at all).

If I take another attempt, it would be in October/November I think that's what my counselor told me, and I'd have to pay since I used up my fee waivers. Should I retake it and ACTUALLY study this time?