For someone who can afford an iPhone+ and usually not the lowest storage capacity, iPhone X is clearly affordable/manageable.
The whole iPhone line up has a price anchoring effect pushing the buyer to consider the next slightly expensive option, from iPhone SE all the way to iPhone X. I know many who are waiting for X, which is ideal for the Snapchat generation of (literally) rich kids as well as the ones who want the most sought after gadgets.
I think the 7+ sales really gave Apple an idea about how much customers were/are willing to spend.
The current price of iPhone X is positioning Apple well for selling an iPhone X+, when/if that ever happens, they can just reduce the current iPhoneX price by $50 and have an X+ for $50 or $100 more.
With the product and price lineup Apple has, its set for a great year in 2018. If $AAPL goes down, imo its a great chance to get a few.
For me, a 128GB 6+ user, the 64gb storage option doesn't work.
My options are: $950 256gb 8+ $1150 256gb X
$200 isn't enough of a difference when the cost is spread out over two years. Why on earth wouldn't I wait 2 months to buy "10" instead of "8"?! when the cost difference is so minor.