$200 difference, if you're looking at the same storage capacity.
The 5C is simply an iPhone 5 in a different case, with the extra dimension required for the plastic vs. the metal casing used to slightly increase the battery size. I don't see what everyone would be expecting otherwise - this is simply going to take the place of the original iPhone 5 (which is now discontinued) as the entry-level phone for people who, frankly, are bad at math, forgetting how much of their monthly bill is going to pay for that "cheap" phone. (This isn't Apple-specific, of course, it's how the cell companies do business - a "cheap" phone that costs several hundreds more over two years...)
No, it's $100:
$99 for a 16GB iPhone 5C, $199 for a 16 GB iPhone 5S.
$199 for a 32GB iPhone 5C, $299 for a 32 GB iPhone 5S.
That's with a two-year contract. Without a contract:
$549 for a 16GB iPhone 5C, $649 for a 16GB iPhone 5S.
$649 for a 32GB iPhone 5C, $749 for a 32GB iPhone 5S.
The 5C is simply an iPhone 5 in a different case, with the extra dimension required for the plastic vs. the metal casing used to slightly increase the battery size. I don't see what everyone would be expecting otherwise - this is simply going to take the place of the original iPhone 5 (which is now discontinued) as the entry-level phone for people who, frankly, are bad at math, forgetting how much of their monthly bill is going to pay for that "cheap" phone.
There are some slight improvements in the iPhone 5C over the iPhone 5, but not significant. The entry level iPhone will actually be the iPhone 4S with 8GB, at $0 with a 2-year contract, and $450 with no contract.
The hope was that Apple would get the manufacturing cost down low enough and set the price so that the 5C would be the true entry level phone (at no cost with a contract). It would also have made it more affordable in the rest of the world where contract subsidies are not typical, and buyers have to pay the full price upfront (or finance it).