Picking up a new smartphone can be a tough decision, especially when you have to factor in things like contracts and carrier locked devices. Thankfully you can usually find some of the devices you might be looking for on eBay or other similar sites if you're looking. The Samsung Galaxy S6 is currently available on eBay for only $639, and that comes unlocked with 32GB of internal storage space. The Galaxy S6 also features a 16MP rear-facing camera with OIS and an f1.9 aperture for better low-light camera visibility, and it comes running Android Lollipop right out of the box. It also has 3GB of RAM on board so multitasking should be no problem at all even for the heaviest users.