I think everyone would agree with this, looking through your cards and thinking "this can be sold" and then seeing it was obtained in adventure mode, a simple filter of unsellable and sellable cards would be good

I have been using just such a filter for quite some time now. It is very useful.

Theres a filter like that?

In the first scroll down box under "Display," the one titled "All Cards" you can select "Salable cards only."

Salable is an adjective meaning "having the characteristic of being able to be sold"

Thus, this option displays only the cards that one holds and is able to sell in the marketplace. It is very useful.

EDIT: I guess there is no filter for "Unsalable cards" though.

I completely didnt notice.....kinda feel silly now >.<