Stapels offers the Seagate 4TB Backup Plus USB 3.0 External Hard Drive, model no. STCA4000100, for $159.99 with free shipping. That's $0.04/GB, $1 under our mention from two days ago, and the lowest total price we could find by $1. Sales tax is added where applicable. It's compatible with Windows and Mac and features two backup scheduling options, social network sharing, and more.