OK... so I am going to most likely be buying a new powerbook w/ edu discounts. And I am going to be getting a 15inch, but I want to keep the price under 2500 as best I can. So my question is which is more important upgrading the VRAM to 128mb or upgrading the HD to 100gb? If this makes a difference I will be keeping this computer for three years, and then I will get a new one for college.