Amazon has a great sale on the Samsung Galaxy S8 and S8+, both unlocked and less than $600 | Mashable
Amazon.com: SAMSUNG SM-G950 Galaxy S8 Unlocked 64GB - US Version (Midnight Black) - US Warranty : Everything Else
Amazon.com: Miqala for Galaxy S8 Case,Marble Design Three Layer Heavy Duty Shockproof Hard Plastic Bumper +Soft Silicone Rubber Protective Case for Samsung Galaxy S8,Purple : Cell Phones & Accessories