Neither; go used. You can get Shimano 105 or 600 from the '80's on the 'Bay all the time for $15-$35, depending on condition and how lucky you are. I ride 105's on my steel Japanese roadie, arabesque 600's on my '72 Bob Jackson roadie, and '87 600's on my Italvega singlespeed; they look cool, wear well, get the job done, and all went for that price range. I even have a couple of 600 cranksets in reserve, against the day twenty years from now when they're hard to find ...