Question about the fingerprint sensor

Haven't seen anyone really discuss these questions I have about the fingerprint sensor.

The majority of the discussion about it seems to revolve around the higher spec iPhone 5S. Do you think that the lower cost iPhone 5 will have the fingerprint sensor as well?

Second, if the 5S and the 5C have the fingerprint sensor, doesn't this mean that the current iPhone 5 will have to be redesigned in order to add a fingerprint sensor? If so, won't this affect Apple being able to push the current iPhone 5 as being the $99 on contract iPhone? Space inside of a phone is already completely used up, adding room for a fingerprint sensor in an already existing design, with the prior years specs seems almost impossible.

It doesn't seem to make sense that there would be an iPhone that is situated in the middle of the other two phones yet missing the hardware ability of fingerprint sensing.

Any thoughts on what Apple will do if the iPhone 5S and the 5C both have the fingerprint sensor?