would building up a bike be a bad idea for a first road bike, currently i have been riding my 27 pound XC bike on the road(slugish). and im looking to get a road bike, i guy i new used to have a Derosa, i thinkit was a steel/carbon mix, or maybe AL/carbon mix, not sure but that was he smoothest road bike i had ever ridden,what do these framescost, and where can i get them, cause i havent been able to find anything in america, i know there expensive, just dont know how much, looking to spend about 5 grand, as i know road bikes last a long time, and want something pretty light