JemJem offers the refurbished Unlocked Apple iPhone 6s Plus 128GB 4G LTE GSM Smartphone in Space Gray or Rose Gold for $499.99 with free shipping. That's $50 under our mention from Black Friday week and the lowest price we've seen for an unlocked model in any condition. (It's also $249 less than you'd pay for a new one today.)
Note: A 90-day JemJem warranty applies. It comes with a non-OEM charger.