When looking at the store and seeing the single cards in the daily deals, I noticed it said I had no Mazemind Tomes and no Linden, the Steadfast Queens. When I went to my collection, I had 1 Mazemind Tome (From M23) and 4 Lindens (from Throne of Eldraine,) but since neither of them were from the Foundations set the store said I had no copies of either.

It would be helpful to see how many playable cards I actually have in the store, as now that I realize it only shows me how many I have from the set that it's being sold from means I will have to stop and go into my collection every time to double check the actual number I have before buying it.