Well the current price rumor is $600-700; I can’t imagine $600 when it’s a replacement for the $699/$799 iPhone 8/8 Plus. Personally I think $749 will be the price.
That said, it does seem a weird feature to use as a differentiator from the more expensive X models. OLED, RAM, camera, lens—sure... but 3D Touch? Who wants that so bad they’ll pay an extra $150?
But it is a new display, so it’s not like there wouldn’t be development costs. And there won’t have been hundreds of millions already manufactured to bring the cost to 4.7”/5.5” levels. So who knows, maybe they did just decide not to include it, from the start.
A lot of users don’t even seem to know it exists. And who can blame them? The UI for 3D Touch has always sucked, with no indication whatsoever where it’s usable. Violates a prime tenet of good UI—requiring knowledge “in the head” vs. having that knowledge presented “in the world”.