Samsung's website is currently selling the Galaxy S8 64GB for just $350. That's $250 off of its regular price. Only the T-Mobile version is on sale for $350, unfortunately. So this is only going to work for T-Mobile customers. Other models are discounted as well, but they are less than $100 off of the regular price. This is not unlocked, and it will be tough to unlock - as T-Mobile does not have these IMEI's in their database.
The Galaxy S8, despite being a little more than a year old, it's still a great device to pick up. This is because it does sport high-end specs. Including a 5.8-inch Quad HD+ display, the Snapdragon 835 chipset, 4GB of RAM, and 64GB of storage. There is also a micro SD card slot available here for expanding storage, if you should need some extra space. There is a 3000mAh battery included, which is non-removable, but it does have Adaptive Fast Charge here. So this is going to be a great phone to pick up for heavy users, especially for $350 right now. It's also important to note that this is only available at this price in the Arctic Silver color. The other colors - midnight black and orchid gray - are priced at $450. Which still aren't bad prices, but they aren't the lowest prices from Samsung's website.
This is sold by Samsung's official website, so you are getting the real thing here and not a knockoff. Additionally, Samsung does offer the ability to buy a warranty - outside of the manufacturer warranty - for this device. So you can protect your purchase. Samsung also has a slew of accessories that you can pick up and use for this device. Samsung's website also offers free two-day shipping on all items purchased on its website. On top of that, they only collect sales tax in a few states