It seems to be the custom here to remove the price once a knife is sold and overwrite it with "sold". Why not leave the price that the knife was listed and sold for and then add the "sold" part to the edit? It lets everyone know what price they may have to pay for a knife or what the market will bear if they decide to sell a knife. On many forums this is written into the rules of the road for sellers. For example, on ar15.com you will have your selling privileges revoked if you remove the price upon selling.