This is from their website.
"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)"

So I should imagine it gets very expensive.