If you are buying from a Ford dealer, then I would tell them that you only want it with the Dec 2017 clutchpack. They should be able to get Ford to pay.
If you are buying, either from a motor trader or privately, then they would probably have to pay for the repair so would try to fob you off.
As I said before, it can only be put right by a replacement clutch pack. It isn't a fault that can be repaired, it is a poorly designed clutch pack which will never work properly.
If you cannot get any commitment from the seller, back off.
I was wrong once but then I could be mistaken.
2014 Bmax 1.6 Powershift Titanium X