The current way the trade columns are set up is a little confusing. I frequently have users doing things like offering me 4 copies of a card that I only need 1 of due to this.
If there were another column like Quantity on other user's wishlist, then it'd be easy to see how many you could bump a particular card up to when you're reworking stuff also. Just a thought!

I'm sure Sebi will review your feedback, but until he does I wanted to let you know that he is working on an overhaul of the trade interface. Things will be changing soon.