I agree, if your getting into the St price range I can't see why if you wanted a quicker than the 125 Zetec s you wouldn't go for an st.
Obviously cheaper tax, insurance etc may sway people but it's still a lot of money for a Zetec s
Don't forget that you will rarely, if ever pay the list price. I would expect these to be around the same sort of price as a red edition.
That echos what my dealer has told me. The petrol version of the ZS will come with the 17"s as standard aswell as the 140hp version of the 1.0 ecohboost from the red/black edition. You'll also be able to have it in the colour 'magnetic'. Not bad!
The engine in the ST is getting a few updates soon too.