I know most of you'll say 'Mroogle' or 'Google it yourself', but I just wanted to ask any of you with experiences. Near my house, there is a computer store which sells Internal HDDs and External Portable HDDs. I wanted to get 500GB, and got stuck with either WD Blue Scorpio or cheaper external portable HDDs. How come the portable HDDs are cheaper than Internal HDDs? Aren't Internal HDDs supposed to be "cheaper" because it doesn't need a case?