Ending today at 9 pm ET, Best Buy via eBay offers the Western Digital Easystore 4TB External USB 3.0 Hard Drive for $89.99. Apply coupon code "PSAVE15NOW" and checkout with PayPal to cut it to $74.99. With free shipping, that's $15 under our mention from three days ago and the lowest outright price we've seen. (It's the best deal now by $31.) It features automatic backup and data transfer rates up to 5Gb/s.

Note: The coupon can be used once per PayPal account within a single transaction