In retaking it, you run the real risk of lowering your other scores.
A 30 S is not a bad score and it sounds like it is really close to what you expected based on your practice tests. If you had been scoring 13s on practice tests I'd tell you to go for it, but for just one point in verbal I don't think it is worth it, especially since your scores are good enough to get in at a number of schools.
You'll probably get a variety of opinions but in the end, though, it has to be your decision.