The Samsung Galaxy S7 is currently available unlocked from eBay for just $449. This is the SM-G950U model, which was only sold as an unlocked model in the US, so it does still sport the same specs as the carrier models, but without the carrier bloat and branding.
Samsung's Galaxy S7 might be last year's smartphone from the South Korean company, but it's still a great one to pick up, and stands head-to-head with today's best. The Galaxy S7 sports a 5.2-inch 2560x1440 resolution Super AMOLED display, powered by the Qualcomm Snapdragon 820 with 4GB of RAM and 32GB of storage. There is also a micro SD card slot available for expanding said storage - up to 256GB. Samsung has included a 3000mAh battery which is not removable, but should last you all day. And there's also their Adaptive Fast Charging included, so you can top off quickly if you need too. The Galaxy S7 is only available in the Black Onyx color, but it will work on both AT&T and T-Mobile here in the US, unfortunately CDMA carriers aren't compatible.
eBay is offering up free shipping on the Galaxy S7, so you won't need to pay for shipping nor taxes, and walk out the door with a brand new smartphone for just $449, which is a great deal. There is also financing available, which would cost you $40/month for 12 months.