This might be the best way to get a Galaxy S8 right now. Samsung is currently having a trade-in promo to turn in your current smartphone towards an unlocked Galaxy S8. This combines the current $100 off along w/ their unlocked S8s.
This combines the current $100 off along w/ their unlocked S8s and this brings the price for one down to $425 for the S8 & $525 for the S8+. This will apply to any smartphone (from Android to iOS) that grants you $200 off at minimum and goes up to $300/$350 off for an S7 Edge or a Note 5. You can trade-in an older phone but you won’t get more bang for your buck.
You can trade-in an older phone but you won’t get more bang for your buck. However, this si a limited offer so make sure to get your devices ready to swap out.