It would be a nice feature if every time "Propose this Trade" was clicked, the card configuration would be put in a "trade configuration history" for that trade. Then each iteration of proposals would be added to the trade history up until the trade is accepted.

Sometimes when large trades are going back in forth, it's difficult to remember what all was on the table as things get added and removed, especially when people start adding stuff from their inventory that isn't in their tradelist.