In Japan, "Carbon Fibre" Vented bonnets start at around A$1700.
But even then, they have an FRP frame. For the street, these ones seem to be the best compromise... they`ve got more carbon fibre than the Carmate ones, yet are cheap enough for the younger guys to get a hold of (not implying $1700 is cheap though!).
Just as a comparison, a REAL full-carbon fibre bonnet from Attkd...
... that weighs a genuine 3.5kg`s, will set you back A$4430. I guess you could say a full-carbon fibre bonnet was for racing use only, or really rich show ponies...