What makes it expensive isn't necessarily the material. I mean, don't get me wrong, but the material is expensive, but what costs more is the labor and time involve. Just like doing body and paint work to a car, there's a lot of labor that's involved in just the preparation. Then there's the lay up which has to be done perfectly to avoid any air pockets or "scrunching" of the weaves in the carbon fiber. Once you lay it up, if you're using vacuum bagging methods, you've got to ensure that you're achieving a proper vacuum that's distributing pressure equally around the part. Then, depending on the resin, you have a wait time usually of at least 12-24 hours. If your mold was designed correctly and you used a good releasing agent, the part should just pop out. Otherwise, you could be fighting the part and the mold, possibly damaging the finished product.
I know of a guy who had a company do him an AAR hood for his '70-something Cuda and it cost him well over $3k.
