if you re-read i said they cost similar to fit n set up but replacement zetecs are £200 if the original goes bang
So your tuned zetec running 9.7 goes bang, and you replace it for £200 ?
Same as if your cossie goes bang, replace it with a £200 transit lump !
If you think you can just buy a £200 zetec, bolt a few bits off your old 9.7sec engine and get it hitting 9.7 again, I think you'll need to think again