Should I bother retaking Subject Tests?

I took them in June and was unsatisfied with my scores (mid-600s). When I took them in November, I did worse (low 600s). I’m thinking about taking them again in January but I’m having last minute doubts. Is it really worth the money/time/stress to take the exams again when I only did worse when I took the test again?

“Insanity: doing the same thing over and over again and expecting different results. - Albert Einstein”

Standardized test scores remain mostly the same unless you put in significant efforts.
If you won’t be preparing for the tests, by reviewing contents, doing flash cards, taking several practice tests, reviewing the errors and understanding why the correct answers are correct, there is no use to take the test again.

Yeah, I ultimately decided against retaking it. At this point, it would be insanity to expect better results with only a month’s worth of review.