WD Elements 500GB 2.5" USB Portable Drive for $71.99 shipped after code L0DGG3?VJ78?V8.  Here is a screenshot for your reference.  This 2.5" portable drive does not require a separate power supply like most external drives.  It is also smaller, making it more convenient to carry around.  If asked during checkout, simply use your name as the business name.  Most places have it for over $90.