For the general "HOW" I use my boat, carbon would probably make sense number wise in more ways than one frankly. I use it for racing more than I do cruising or equal. Then again, I went on a 3 hr cruise the other night on an old peterson war horse that is alum and rod rigging, still gets into the 48N top 25, despite an old IOR design, ie "Shoot the Moon" Well balanced and quick mind you.
If i were to go new, and carbon were an option, I would go for it frankly. Probably do so if my alum bit the dust. But as you say, everything has a number including the dollar number needing to add up in the end. I would probably need to see the difference in righting moment to decide if the difference was worth it or not. or amount of rail meat I could delete......again, more numbers to play with, confuse one.... or make sense of something...... in the mean time. I have aluminum and SS rigging, all original, so probably need to dismast the boat, redo the SS, may go to rod.......keep the aluminum, already have dyneema lines, and laminate sails. No dacron or sta-set on my boat! I am sure a carbon mast would help, just how much......now that is another story.......
She drives me boat,
I drives me dinghy!