Ah, found these:
Cost of crashing on the Nurburgring
These include Armco repairs, safety car attendance, vehicle recovery, track closure, hospital stays and helicopter fees. I recommend avoiding these. If you can't, then the following price-list may help:
Base fee for attendance of armco truck: €150
Removing damaged armco: €10/metre (x2 or x3 or x4 for multiple-height sections)
Replacement armco: €31/metre (x2 or x3 for double/triple height)
Removing damaged armco posts: €5.10 each
Replacing armco post: €39 each
Safety car attendance: €82 per 30 mins (car + 2 people)
Circuit closure: €1,350 per hour
Recovery truck: €250 (inc VAT)
Hospital stay & air ambulance: Let's just say, do NOT go there without travel insurance! (Though a European Health Card - which replaced the E111 - may cover the hospital bit.)
Everything except the recovery truck is then subject to 19% VAT.
The record armco bill I'm aware of is €15,000. That was a car that managed to flatten a very impressive length of armco between the Quiddlebacher Hohe bridge and the crest on the approach to Flugplatz. But even a minor bump can turn into a surprisingly expensive day out.