would it be a complete replacement or jsut the stock piece with carbon fiber layed over it? im assuming since you want a core back, that its just laid over the stock piece. which isnt a problem, youre not gonna gain anyhting from replacing it with a full CF piece, and it doesnt require making a mold... which should bring down the price. of course with carbon fiber prices these days (if you can get the stuff), $120 seems reasonable... but at the same time, i would _assume_ prices on these would reduce after the shortage is over.
also, do you have a source for carbon fiber cloth? i know theres a world wide shortage ATM thanks to our buddies at boeing, air bus and some ship builder that does navy ships buying almost every last square yard of the stuff on the planet... makers of CF cant keep up. i know theres a couple places that have a limited supply, but the price is really high on the stuff, almost tripple what it usually is (about $25/yard or so, depending on where you go, i used to know guys who could get it to me for about $19/yard - not pre impregnated stuff, just raw carbon fiber cloth).