Post an asking price for everything you're selling. If you don't know what to list it for, search the FS forums here and other classifieds like those on dsmtuners.com and tampabay.dsm.org to get an idea of a fair price. Pretty much anything you could want to sell has been listed and sold in the past. Even if you just guess at it, an asking price gives interested parties a general idea of what you want for the part and is a starting point for bargaining.