£2k including fitting is what I heard - I know the unit costs over £1k at least.
They said they are making a goodwill gesture considering the age/mileage of the car and the fact it has full VW history.
I previously read of them offering the same deal so I'm very happy with the outcome and the fact I didn't have to jump through hoops to get it. They simply phoned me up and told me the mechatronics unit needed replacing and they were going to pay towards it, although the unit takes 10 days to be shipped from Germany.
The fact the car is under 4 years old (just) may help.
VW know it's a common problem so keep pushing for it if you have any trouble getting a replacement!