Airplane - Took my Sonex almost to VNE, 165KIAS. $30,000/165 = $182 per knot.
Helicopter - In about a 70 degree dive, > 200KTAS, the helicopter did not use or easily display KIAS. Well beyond VNE. Very little symptoms of retreating blade stall. $35,000,000/200 = $175,000 per knot.