Ah, I personally don't think a separate sub is needed for that. You could just list the item in the goods section asking if there's any interest in it and what people would potentially pay as I have seen a few users do this before, but I don't think enough to warrant its own section (though others may disagree).
My opinion is that an appraisal sub would be usefull because unlike the goods section, people that visit it wouldn't necessarily be looking to buy or sell something. People would get the chance to ask for appraisals on items they aren't even looking to sell just to see how much they're worth.
The value of what you are wanting to sell is ultimately what the buyer is willing to pay for it as well as how quickly you want something sold. If you are willing/able to wait then you can likely wait out for a higher price, but if you need cash asap then you will need to sell for a lower price
