Collection Customization
I've only used the site today but really like it. Would love to see some subgroups or labels to be added into the collection features. And they're can never be enough filters for this. The more categories to organize by, the better.
Glad you like the site so far. I'd love to hear more about this idea. Would people add a label to items in their collection like "to sell", "upgrade condition", "sent for grading", etc
Then you could filter your list to include cards with those specific labels?