In my experience, if you find a knife at a secondary market venue and feel the price is too high, dicker. One tactic that is often sucessful is to average down the price by bundling. One example is to gather up $150-$200 worth of marked knives and lay a $100 bill down beside them. The seller will accept or not. If it is only a single knife of interest and it is priced too high, lay down the green you think it is worth to you. If the seller won't come down, then walk. Many will eye the bills and change the price. You may be there for the knife, but they are there for the money. Show them the money. If the knife is junk, hardly good for parts, then you lose nothing by walking without offering. However I don't suggest laughing or otherwise insulting the seller. Thank them for letting you chickeneye and coon finger the knife and let them know what you are looking for. They may just have more knives in a box, drawer, at home or in their pocket.