I understand your dilemma but to be really honest, if your accuracy varies greatly across all sections I wouldn't recommend that you give the exam in 8-10 days because you won't be able to rectify this problem in such a short span. Unless you have very compelling circumstances its better if you postpone.
If you do decide to go ahead then you could score b/w 600-650 (on the basis of your current situation) btw R2 deadlines are almost over so there shouldn't be a rush to give the test (do correct me if I'm wrong). Your score variance could be because you concentrate on a section/ topic in isolation without revising/ reviewing your previous work and there are always some topics in each section you find difficult, you need to work on those as asap. you haven't mention your q/v split so i can't say which section needs more work , if its verbal then SC is most learnable (for most people) in a short time span. if its quant then please get topics such as- divisibility, prime nos, remainders, exponent, mean-median, algebraic equations, %, fractions, time & distance in order. gmat culb math books is great source for revision.
Ron's videos are great , but their techniques take time to be internalized esp CR, quant back up methods, etc. and most importantly If timing (failure to complete any section or rushing towards the end ) is a problem get it out of the way first because than alone can boost you score by 30 points or so (I'm quite serious about this).
May be going through these articles below can help you makeup your mind-http://www.beatthegmat.com/mba/2012/12/ ... ore-i-want
how to analyse you mockhttp://www.beatthegmat.com/mba/2009/09/ ... tice-tests
Whatever you decide to do, good luck
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