Yes, there are carbon fiber acoustic guitars available at various price points. They are much less affected by changes in temperature and humidity than wooden guitars. RainSong is one popular brand while McPherson cater to fatter wallets.
Are carbon fiber speaker cabinets inherently better than wood or metal ones
There seems to be a pretty big jump in speaker prices when moving to carbon fiber cabinetry when all else is equal (or what seems like equal). Is this because it is able to be molded into more acoustically correct shapes or simple the characteristics of the material?