I have $200 I can spend at Best Buy in Rewards and a Gift Card. I want to get a replacement large external HD. Right now I currently have two old 500gb Western Digital HD's connected to a USB 2.0 hub into my AirPort Extreme router working fine, but both are out of space. I want to get an external but my worry is I also don't want to lose the data on the external if that one drive dies. So how do I go about preventing that with my funds I do have available? Any ideas? One of my 500gb backs up time machine for my mac products the windows PC while the other one is my DATA drive right now.