This is a bit simplified, but here's how a store manages Magic product
She has Singer three , meaning that she can sing songs with a cost of three or less for free , but otherwise, that's it
Pokemon Singles: They are a more cost-effective way to getting the exact cards you want without relying on the RNG of opening booster packs
Exiling the card from your graveyard is part of the cost, so once scavenge has been activated, its too late for your opponent to try to get the card out of your graveyard to stop the scavenge
Esper Sentinel There could be no other pick for the best MTG white card draw spell than Esper Sentinel , white's Rhystic Study equivalent
Proliferate Decks - In decks like Five Color Planeswalkers with a bunch of proliferating to raise the loyalty counter count, this can be used as a win con with just one or two hits turning into wins