Not sure if this applies to everyone but I for example always try and get at least two of each decks, one to keep sealed and one to open and enjoy the art. Sometimes I even find a deck that I don't have in my collection but it is already used and therefore open.
So I would suggest adding an extra count for number of open decks that we have. So for each deck we'd be able to mark how many we 'Own (Sealed & Open separately), how many of those are for 'Trade' (this number shouldn't be higher than total number owned) & lastly how many are on our 'Wish List'
I don't think it's a very important addition but it was an idea I had because that's how I try to categorize my collection