Indeed, the 5c is just a bad deal; You get the iPhone 5, a model that would've been reduced in price anyway if they retained it, with no big/significant changes other than a plastic shell (downgrade if you ask me). Thats fine if they'd set the price to say $399, but at $549 you would be mad not to lay down another $100 for the 5s.
"Listen. Let's put one mid tier phone on the market. Make it expensive but not necessarily any better than its predecessor. Then, we also release a phone which is actually an improvement. Our flagship, if you will. The trick is in making the mid tier marginally cheaper than the flagship. This will make the step to the flagship a lot smaller and as the mid tier is basically its predecessor with a few tweaks and a new housing, the average Joe will not even complain. We are getting rid of the old iPhone fives, improving sales for the more expensive variant and it doesn't cost us a thing!"
Actually I've read this (in a more elaborate version) in either Priceless or Influence (maybe even some hints in Scientific Advertising). Which are two very good reads if you are in anything related to sales, money or almost anything else. It's something I've applied many times and works wonders.
Many iPhone users seem to personally be on a 2 year cycle. Depreciation circa $300 / year.
Many others seem to be on a 3 year cycle, about as far as one can go before starting to really notice their handset lagging to the point of being unacceptable to them. Depreciation $200/year.
5c: Year old tech, in what for many will be "less pretigious" packaging, for $100 off the price of new tech in "more prestigious" packaging. You're immediately "out" $100, or $200, depending upon whether you are on the 3 year or the 2 year cycle.
$100/$600, for a savings of 17%. For 17% off, you're taking year old tech in a less prestigious package.