eBay has the Apple iPhone 6s 16GB 64GB GSM 4.7" Smartphone (Space Gray, Silver, Gold or Rose Gold) refurbished for $280 with free shipping. Features 4.7-inch (diagonal) LED-backlit widescreen multi-touch display with IPS technology, new 8-megapixel iSight camera with 1.5µ pixels, A8 chip with 64-bit architecture. M8 motion coprocessor, 1080p HD video recording (30 fps or 60 fps).
Has good Amazon Reviews.
eBay has the Unlocked Galaxy S7 32GB 4G GSM Phone (Black or Gold) refurbished for $200 with free shipping. Features a Qualcomm Snapdragon 820 2.2GHz quad-core processor, 4GB RAM, 32GB internal storage, 5.1" 2560x1440 AMOLED touchscreen LCD, 12-megapixel rear camera, 5-megapixel front-facing camera, 4K video recording at 30fps, 802.11ac wireless, Bluetooth 4.2, microSDXC card slot.
eBay has the Samsung Galaxy S8 Dual SIM Unlocked 64GB 5.8" Smartphonel (Black, Gray or Gold) for $590 with free shipping. List price: $810. Features Exynos 8895 Octa-Core (4x2.3 GHz & 4x1.7 GHz), 4GB RAM, 64GB storage, 5.8" Infinity display (2960 x 1440), 12MP cam, 802.11ac, Android 7.0 Nougat.