Not very many, as they probably would have been about £100k each. They were never going to develop a brand new body shell for this one car. 90% of Focus buyers want a 5dr, it's just not worth their effort to make a 3dr Focus just to keep a handful of crusty enthusiasts happy.
They'll sell every single one that they choose to make. They're not looking to sell 100,000 of them. It's already been a massive success and done everything it needed to.