Not sure if this has been suggested before, but I think it’s a huge step in making a much sleeker and easier to use trade system to make a relevant trade a lot more easier to set up.
The option of seeing duplicate cards, and cards not owned by the tradee, is very useful; However, there should be a button to see which series both the Trader and Tradee are collecting! This way, if you want to offer cards from another series from the one you are trading for, you don’t need to look through an entire list to see which series they are collecting that you also have cards for. There is the new wishlist button, but that’s not much help if they haven’t added to it haha.
Hopefully this gets implemented as I love the site and this will make trading so much more attractive to use!