Welcome Kymco Owners!
You want to buy used brake rotors that are like new? Or do you want to buy a wrecked bike with 5500?Used brake rotors where you still see the pretty grinding marks will have very little wear. Next they must be straight. To check that they must be either on a wheel or in a lathe.Okay, I re-read your question : the brake rotor is on a bike with a crash on the front. As long as it is straight (which is unlikely) should be good.
BREMBO offers, at least here in Italia, brake discs in top quality for €56,- apiece. A set of new bolts is €10 -, if you cannot check them before you buy, get new ones.
sounds good price can you send me a link?