Another numbskull ANAL-yst giving his 2-cents, worthless as it is.
Apple will build an inexpensive iPhone when it can do so. This means it has to be an iPhone - with all that it means.
Apple actually already has been selling an inexpensive iPhone.
The iPhone 3G, 4, and 5c have been selling for FREE with a contract on many carriers. That is pretty cheap if ZERO is considered cheap.