Don't you love when smartphone prices drop to a point where what counts as a high-end flagship starts becoming affordable again? In this case, the Galaxy S9 is around the corner and that explains why prices for the S8 and S8+ will see some significant discounts now, but if you can't wait and want a good deal this very moment, there's one to be had on eBay.
best_deal_today, a positively rated seller, has open box units of the Galaxy S8 G950U 64GB on discount for $475.95. This is the US factory unlocked version of the phone and according to the description, these were display units or excess inventory and have been checked, tested, and cleaned. They look and work great and are in "9+10" condition, which I assume means 9/10 or 9-10. They come with a wall charger without any mention of other accessories, and there's a 30-day return policy in case you don't like what you get.
The seller will ship to the US for free, and many other countries as well though shipping charges and taxes might apply then. If you're interested, you might want to make up your mind quickly as eBay is showing the dreaded "Limited quantity available" notice and only the Midnight Black color is still listed.