It would be helpful to know what sort of PC Parts they are and how old they are. Are these complete PC's or just a selection of spares?
I sell old spares on eBay but to be honest mine are just mainly laptop components which are at least 4 years old and after eBay and PayPal fees (Say 15%) plus P&P I'm lucky to make a Half Pint out of it! LOL
It is not a great deal of effort but you have to be patient. Some items can be listed for months before they sell.
Over to you - what you got?