Some real long time ago, in the Future Sight set, there was an ability that allowed us to spend much less mana to cast certain spells in a late game when the graveyard was full of cards
For instance, some suppliers offer significant reductions (e.g., from $73 to $68 per box for orders exceeding 60 boxes)
Drawing 2 cards is good, but the kicker is this sets up for bringing Pawpsicle or other items back to do it again
Second, its harder to get caught up in the trap of having the wrong mix of cards in hand, as sometimes happens in combo decks and prowess decks
I agree that its something that could truly benefit from being documented thoroughly, and youd be doing the community a huge service
Not only is it a way to get potential threats out of your way, but you can also even flash in the creature half if you need to block a flying creature coming at your face