i am redoing the entire interior so i am looking for everything but at a fair price. i would like the leather seats in black if anyone has them for sale.

Sometimes used part are good choices.  I have a mixture in my restoration.  But when it comes to plastic parts most used parts will be of little use as they are brittle and if not broken will break when installed just keep that in mind. 

Other than that depending on where you live you may be close to someone that restore C3s and parts out the ones that are not restore able.  Like I am in San Diego.  What part of the country are you located.