Where can could get 3 1TB HDs for $200?
NewEgg, TigerDirect, etc.
kpac is referring to Internal hard drives; since there is literally no difference. a External hard drive, no matter how you slice it, is always an internal hard drive thrown in an enclosure. Same with external Floppy drives and SuperDisk drives. That is why I find it outrageous that you can often pay almost 50% more for what amounts to a few flaps of metal or plastic and a cheap circuit board to perform the adaptation between SATA/IDE to USB/Firewire/whatever. you can get sturdy enclosures for 20-40 dollars that are often a lot better then the externals many companies sell, not to mention that you can choose exactly what goes inside.
Actually, this brings up an important point. We don't know that the 3GB external drive doesn't actually have 3 1TB drives, 2 1.5TB drives, or a single 3TB drive (as we are all assuming). I'm apt to think it's one of the first two, especially since it's snugly sized to fit exactly two 3-1/2" hard drives.