You're looking at it wrong. The iPhone is overpriced not in relation to its competition, it's overpriced because Apple's profit margins on those things are the highest in the industry. Meaning that, per phone, their markup is above and beyond anyone else (WAY above and beyond). They boast about it all the time and I shake my head... I mean, they are openly admitting that they over-inflate the retail price of the phone and everyone in the audience applauds. That alone illustrates to me how blindly loyal their customer base is...Tim Cook: "We're overcharging you and making BILLIONS!" Customers:"HUZZAH! WE LOVE APPLE!"
And they can pull it off due to zero in-platform competition. I mean, you don't have some upstart outfit pumping out iOS compatible devices for half the price. I remember back in the day when I worked at a computer store. We had some Macintosh clones.... they ran great, just as good as the Apple products in all but one area; price. They cost like half as much and we sold a ton... until the company lost a court battle and had to pull them from the shelves.
I always wondered what effect it would have if Apple took, say, the Nexus 5 and got iOS fully ported to its hardware.... then put it on sale at the Apple Stores next to the iPhone 5S for $399, undercutting the 5S by, what, $200? Of course it would never happen, as it would pull back the curtain and illustrate to everyone involved just how much Apple was gouging them on the iPhone.
Now, I'm guessing that they 6 might change the equation a little bit... that might have a higher unit cost than the 5S, but I bet you they'll still play the "OUR PROFIT MARGINS RULE!" trumpets at some point. And no one connects the dots.