I'm not saying there will be two chips on the board, all I'm saying is that it's possible.
Also, remember, they have a bunch of wiggle room between the manufacture cost of the phone and the selling price of the phone. If they eliminate the old style phones from manufacture and concentrate on the new model at 16/32/64GB models, they will save money and possibly be able to hit the $99/199/299 price points.
I don't see Apple deviating from those price points, but maybe they'll go with $149/249/349 if they do an all 4th gen lineup of 16/32/64GB.
Also, remember, they have a bunch of wiggle room between the manufacture cost of the phone and the selling price of the phone. If they eliminate the old style phones from manufacture and concentrate on the new model at 16/32/64GB models, they will save money and possibly be able to hit the $99/199/299 price points.
I don't see Apple deviating from those price points, but maybe they'll go with $149/249/349 if they do an all 4th gen lineup of 16/32/64GB.