It sucks big time for me since I turned 18 this year and I'd like to get C1E, but it is pretty much impossible for me at the moment.
For C1E you need to have had C license for 12 months minimum and be 21 to get it with just the driving test and multiple choice. If you are under 21, you need to get 200 lessons of training with driving instructor (1 lesson= 25 minutes of driving)
C lessons were 35€ per lesson from the school I got my teaching and I guess that the combination lessons are even more expensive