The Western digital Passport is only $50 for a 1TB:
Amazon.com: WD 5TB My Passport Portable External Hard Drive HDD, USB 3.0, USB 2.0 Compatible, Black - WDBPKJ0050BBK-WESN : Electronics
And you can get a Y-cable for $10 (or less if you look around):
Amazon.com: Cable Matters Micro USB 3.0 to...