I have been waiting to purchase a new MP for the past 2 months, I was planning to go with the standard 2.8 Octo but last night I noticed at the Apple website that they had the refurb 3.0 Ghz dual quad core for $2499. The refurb unit had the 7300GT, 1 GB of memory and a single SD, looking for suggestions as to which one is the better buy? 