PC on Corrupted 6L Brain Rattler with Onslaught Support

I corrupted this a few days before the new Onslaught change which gives "Supported Skills have 10% chance to grant Onslaught for 3 seconds when you Hit a Unique Enemy." Comparable results range from 8EX to 25EX, what would you price this at?

1 off maximum min damage (80-100), and 6 off maximum max damage (320-370).