"Samsung doesn't charge as much.."
I just proved that wrong. In the US they charge more. It doesn't matter if they only charge more in one country, my point is still valid.
Has nothing to do with the world being larger than the USA. I'm using the USA as an example.
Edit: Lets use UK as another example.
iPhone 7 128GB = 699
iPhone 7+ 128GB = 819
S8 64GB = 689
S8+ 64GB = 779
Again spending pretty much the same, but for 2x the storage.
What about Australia?
iPhone 7 128GB = 1229
iPhone 7+ 128GB = 1419
S8 64GB = 1199
S8+ 64GB = 1349
So again, pretty much just as expensive but you get double the storage.