i won’t speak for Lord M but I think the preference was one coin. I just didn’t have any one coin that fit the bill and I wanted him to get rolling again.
Either. Any trade that is coin-related and worth a little bit more than the item I have. Can be multiple coins, or a single piece, though I prefer single pieces since that simplifies things. I can't be too choosy here, since this whole game leans heavily on the generosity of my trading partners.