I doubt if that was the original strategy. However in Summer when they looked at the figures for production, they probably thought that they would get lots of orders for the 5C anyway from Japan and China, and other new markets and there was no need or available capacity, at least in the run up to Christmas/Chinese New Year to sell the 5C at the lower price - which would mean the price of the 4S. Or they have a newer product to come early next year. Or both.
However they now have a pricing model where you pay $100 for more storage in the 5C, or $100 for a faster chip, 64 bit arch, M7, touch screen, faster GPU etc in the 5S. I bet sales of the 5C higher end model are low.
You got to be kidding???? Apple plan the production in Summer??? When did they order the parts for the 9M 5s and 5c they sold and how long will the supplier take to produce and deliver all those parts to Apple? Look at how many version of 5s and 5c that Apple produced around the globe. There are at least 5 versions of 5s and 5c (A1530, A1528 etc. etc.) around China region. Producing that many version of 5s/5c on top of the color/capacity variation is an organized chaos. Apple has to talk to the telecom around the world 9 months or so before launch about the features of the phone and price point of the phones. And once they gather all the order from telecom around the world (and their special requirement in term of LTE bank that their phone will support, GSM vs CDMA, TD-LTE vs FD-LTE), Apple need to figure out a launch plan and production plan that go with it. And the production plan depend on the the parts from suppliers and the order has to be in at least 6-7 months for the long lead item before production started (think you can just walk in and ask Qcom to ship Apple 9m of their LTE chip with less than a few months of ramp up time is just plan carzy).
4s has been a pretty good products for Apple last year when Iphone 5 was the latest toy. You can make the same argument last year for the $100 difference and you get the latest toys. But yet 4s sold pretty well. And you can make the same argument about 4 vs 4s last year. If you have taken any economic 101 course at all, you know demand is elastic. And there are people who won't spend any more than necessary. The new toys in 5s is wonderful for the tech orient guy/gals (I have a 5s now), but for someone who is not interested in tech feature (e.g. my wife), 5c is doing perfectly fine. Why would they spend another $100 for features that they don't want? The number of 5c sales may not be as high as 5s (btw we need to give the 5c activation data mature a little bit more before we can tell the split between 5s vs 5c). But 5c sales bar is not set against 5s. The bar is set against the 4s sales last year.