BuyDig via eBay offers the Western Digital 1TB My Passport Cinema 4K UHD USB 3.0 External Hard Drive, model no. WDBZKS0010BBK-NESN, for $49.99 with free shipping. That's tied with our March mention as the lowest total price we've seen. (It's a current best by $27.) It comes preloaded with 4K UHD titles and features transfer rates up to 5Gb/s.
Note that it requires a Vidity-enabled UHD TV.