Lap prices are up again for 2012.
1 lap: €26
4 laps: €95
25 laps: €490
Jahreskarte (year pass): €1445
So in 2011 we lost the 8 lap pass and now we've lost the 15 lap one too.
The 'ring management really is taking the piss with pricing for TF days now.
Better off going on a private trackday. Circa £400 - £500 for a day of unlimited laps, cars only, use of the full Dottinger Hohe straight and due to the track discipline of the attendees you should see a full day with limited (or even none/no) closures.
You can do more laps in that one day on a closed trackday than you could on a full weekend of public opening.