Its also used as a way to have a graveyard-like zone with little to no interaction
Squirrel Wrangler Market Price: $2.30, Foil: $35.40 The third-ever card in Magics history that dealt with the Squirrel creature type - after Liege of the Hollows from Weatherlight and Deranged Hermit from Urzas Legacy (the second-most valuable card from that set) - this 2/2 Human Druid for asks quite a bit of you
Sensei's Divining Top Market Price: $42.87 It's so good, it's banned in Modern and Legacy
He loves card games, puzzles, platformers, puzzle-platformers, and lots more.
It doesn't actually add any cost reduction, so you still pay full price, but if you happened to mill the cards into the graveyard or discarded them to an effect, you can still have access to the cards