I wish I knew :) . I only can tell you from my experience that the MBA program is not a surefire way to improve your salary - maybe the top MBA programs ARE surefire, but they're also really expensive and hard to get into.

If you can get a company to fund your MBA, that would be great.

Also, I don't know where you live, but I think that anywhere in the world (including NYC and SF), 300k is an unbelievably large amount of money. You might be losing perspective if you think it's not.