Nothing wrong with used parts IMHO. That just means that if you need, say, a driver's front fender, they'll take it from a wrecked car in a junkyard that was rear-ended or something. It will still need to be painted to match your car so it'll have fresh paint on it by the body shop. With a lot of older vehicles I'd even PREFER rust free junkyard parts because they may fit better than what NOS parts are out there (what's left is often the end of the run when the tooling was getting worn.) It's also ecologically correct, if you care about stuff - the PC name of "auto recycler" for a junkyard is actually accurate.
I would be wary of new aftermarket though. My dad and I used aftermarket doors on his '73 Chevy pickup when we fixed it up the first time and that was a mistake, should have had rust free door shells shipped from Arizona.