All weapon and armor have increasing cost.While the effect per point is linear.so the curve is easier at start and hard at the end.
CoBF have linear cost per point and linear effect per point.So the curve is costly for the early point 100K per point while most weapon dont reach that price before x40 or so.
In the long term weapon will reach a point that increasing the X by 1 point will cost 1 M and while CoBf whille still be at 100K per point.ToP Pr team will have some huge CoBf +250 vs MH X112 +89 i let you guess wich win between teh wall and the tank or ToA tank.
So CoBF should have a increasing cost per point to have similar curve to weapon armor and rewards.That should solve the issue in the long terms and for now.Similar change as been made in CB1 with the + on bow.