If you like to collect, restore and ride classic road bikes, as I do, remember that a mixed tubeset frame with a Reynolds 531 or Columbus main triangle is 99.5% as good as its much costlier full-Reynolds or full-Columbus top-of-the-line cousin. Can't afford a Peugeot PX-10? No problem -- look for a PR-10 or PKN-10, which will ride just as well, but weigh an unnoticeable extra 100 or 200 grams. The same goes for a Bianchi Campione d'Italia versus a Specialissima or other snooty Reparto Course offering. The critical elements, i.e., the frame geometry and the main triangle, are the same.