Samsung's value varies thought the refresh cycle. Last month I bought a brand new Galaxy S8 for less than a OnePlus 5T costs. I wouldn't have bought it at full price.
I'm hoping that I'll get even more value from it by keeping good care of it - glass screen protector and tough case. Waterproofing is reassuring, as is wireless charging (which means the phone remains usable even if its USB connector gets damaged).
The Samsung software / skin isn't quite as annoying as I feared.