If they put the 6 guts in this thing with Touch ID and Apple Pay. Make it the 4 inch screen and cheaper they would make a killing.
Yes, they would sell, but would Apple make their money on them?
If they get rid of 6 body, moving it to this 4" plastic, selling for $100 OC... they could make their money, perhaps... (if a complete 6 cramming in is possible)
::But, what would be free? 5s?::
Another option is to use 5s internals in plastic and sell $0 OC...
::But, what would be $100 OC? The same 6 body from 2014?::
There's the camera hole problem... If they cram the current 6 into 4" plastic body, then wouldn't they have a round flash for it?
Contrariwise, if they use the 5s internals in 4" plastic and added

Pay, why should the 5S users who prefer 4" buy it? Just for

Pay?
(I'm just being hopeful here, but I really hope that the answer isn't: "The iPhone 5s users are going to be completely satisfied with either a 4.7" 6 or 6s". Seriously. F that. Person pays $200oc for the 5s and prefers to get an updated 4" device. Even if it's -1 year performance, and $100oc less, that's reasonable expectation of consumers. But to only make a 4" device that is -2 years in performance, essentially a 5s, and offer it at $0oc... that's F'd. Offer a reasonable device option for 4" lovers.)
At least the iPhone 5c lead-up two years ago was a blast to follow. Very, very interested about this 6c.