Look at your local bestbuy.

DONT FLAME ME.

Right now 99% of External HDs are going to Firewire or E-SATA so with that being said bestbuy is clearancing out there older models. I got a simple drive 1TB for 60 bucks.

If you want portability then get something 500GB or less because anything more you will need a secondary power source.

Just curious what is the reason you are buying an x-HD?