Usually when going carbon it's not about being cheaper than replacing plastics, it's for appearance of the carbon and the weight savings. Most of the weight savings is negated just because everyone wants the high gloss carbon look with the glass like finish. To accomplish this, the manufacturer has to use excessive resin. Add paint and it kinda defeats the purpose of going carbon at all. Unless it's Kevlar backed it isn't really a fan of impacts so it's no better than the plastic as far as durability goes. Actually it's probably far worse.