Hi Ghensky,
While I'm sure that you could potentially learn a great deal about the GMAT in just 1 month, many Test Takers spend 3 months (or more) of consistent study time before they hit their 'peak' scores. The goal to raise a 380 to a 550+ in just 1 month might be too tough to be considered realistic. Of course, no one here knows you well enough to tell you what you're truly capable of. To hit 550+, you don't have to correctly answer ANY questions that you think are too hard or to weird, but to improve 170+ points, you do have to keep the little mistakes to a minimum.
1) What is the exact application deadline for the School that you're interested in? Is there another (later) application deadline (and if so, then what is it?)?
2) You mentioned that a '550 minimum' is needed. Will that score 'guarantee' you entry or are there other qualifications that are needed?
GMAT assassins aren't born, they're made,
Rich