To be frank,650 from 300 seems very steep cliff for me not impossible but not easier as well.

The best i can think of is:may be you may buy some online courses from kalpan,princeton etc and practice for gmat and let the expert carry out your diagonosis test and interpret result and suggest you right way.

Did you take a GMATprep test and see where you are? A 410 in Princeton test means you need to work much more harder. But try taking a GMATPrep and then evaluate your position. A score of 600+ in GMATPrep means that you're pretty close to your target score and if you plan a more smart study schedule in the next 2 weeks can definitely take you to a 650. Otherwise, consider re-scheduling the exam.

@papgust,

I think the reason I got 410, is because I was speeding too fast (I finished the math 23 mins earlier and verbal 19 mins earlier)

Is that true, "its better to answer a question, even wrong answer, then to leave questions unanswered, because you will lose more points for not answering question right.

stech786 wrote: Is that true, "its better to answer a question, even wrong answer, then to leave questions unanswered, because you will lose more points for not answering question right.

Yes indeed. You should never leave a question blank. Your percentile drops by a great margin. Make an educated guess if you're not sure of the answer.

As you say, a 410 might be due to your speediness as well. You haven't timed your questions properly. Going too slow or too fast ends in problems. As I said earlier, take a GMATPrep now and evaluate your position. This test is the most accurate predictor. This will be a deciding factor for you whether to go ahead with exam or to re-schedule.

It seems you have two weeks.I assume you have devoted quite a lot of time practicing and getting to know the nitty gritties of the test.
Week 1: intensify your prep as much as you possibly can. practice 30 questions of each type per day atleast. Give 2 tests atleast. Go though the OG-12 thoroughly. Dont just solve the questions in less than 1 minute saying "I know this question I have solved it many times." Go thorough the explanations thoroughly.
Week 2: Take it a bit easier,which doesnt mean take it easy though. Solve a few questions and give 2-3 mock tests,preferably GMAT Prep tests even if you might have attempted those tests multiple times. Try to mimic test conditions as much as possible, which includes attempting the test alongwith the AWA section.
Finally dont stress out on the test. Afterall, GMAT is just one of the parameters.