690 is a decent score. I'd advise only retaking if you have a strong imbalance in your quant/verbal score that might be placing you on a waiting list.
The jump to the 730 range is not easy. We do have students who have made the leap - for example Kang Cao (http://www.gmatpill.com/the-gmat-pill-m ... l-student/
) who went from 690 to 760 and got an outrageous scholarship - but such improvement should certainly not be expected by simply enrolling. Always hold yourself accountable to the highest standards and visualize your success in the same way Olympic athletes do on a regular basis.
You are welcome to look at the many reviews of our program around the web. And we wish you the best whichever approach you choose.
Good luck! Focus, focus, focus!
... and more
What's Inside GMAT Pill?
Zeke Lee, GMAT Pill Study Method (Study Less. Score More.)
GMAT Pill Reviews | GMAT PILL Free Practice Test