Like has been explained, this isn't an auction site, we've been down that route before.
If you want to put a link on here, put a price on what you'd like for the item and negotiate from there. You can alternatively query how much someone thinks your item is worth if you're not sure but that would be on one of the other forums NOT the for sale ones. You can also do an advanced search in Ebay and look for completed items to give you an idea of how much things sell for second hand. Bear in mind that items tend to be a bit cheaper on this site than on Ebay.