I like it when all items are priced, if they are for sale. I think you should price everything, if it is for sale. If you are willing to trade, state that in your listing. Item is $XXX or willing to trade for "described item." If you are just here to trade and trade only, no price is needed. Curiosity in what they are looking for will force interaction if there is something posted that you want bad enough. Leave it as it is. If someone wants to trade a 60 for a paper can, I hope that I have the paper can. If both parties are happy, that's thier business.