I know, lame heading
I have one "practice run" carbon fiber LH rear arch. I has some minor defects which can be filled with either resin or clear coat. If I remember correctly this one has glass fiber between carbon to reduce the cost a bit. Sold as seen in the pictures. £60 (70€) +postage, this covers just bare material costs for me.
Want RH side as well? If you want this LH side+one brand new RH side it would be 250€
I can make it or pretty much everything for R5 in carbon or glass fiber for the right price.
edited; changed currencies to euro and added total price for LH+RH