Perhaps this is already an option and I have overlooked it, or this topic has already been discussed elsewhere.

To elaborate.  If I have a particular card I am looking to trade, and I search the users that have said card on their wishlist, I am taken to the trading opportunities page and can only filter by users who also have a specific card I want, or at least one card from my own wishlist.

I think it would be grand if I could simply and specifically look over each user who wants the card I have.  I don't always have my wishlist up to date, nor do I only trade specifically for what is listed on it.  Often times, I find cards I want simply by looking over other users' tradelists.  IE I don't always know what I want until I see it on someone's list.