I don't think he's talking about a trade. At the end, he was just saying that he's on the same boat as he's in the same predicament looking for a domain that with a different TLD.

I've never been in this situation before so I would just ask what he's willing to pay for it. That will probably give you a rough number to work with and maybe you can ask for a little more. Sorry I can't give you an exact number. All the best.