I think you are too hard on yourself though I understand this is between you and GMAT - I also think that with 730 you can comfortably get into the school of your dreams. You have a lot of ambition and that in itself is a quality. Thank you for your post.

I am a 30+ year applicant. I was told you must have a very strong application to enroll at certain schools not as much at others (in Europe for instance age is less important). So no clear cut answer but it is definitely worth the try.