Many of the lands you want to target with Grazer enter the battlefield tapped anyways, so this offsets what would normally be an additional cost
This card is pretty much a reprint of Zoroark GX from Sun & Moon's expansion Shining Legends, but with some more modern rebalancing as that card was notoriously one of the best in its era
Control decks in particular make excellent use of Swords to Plowshares since they typically don't mind giving the opponent life
It's not a card you want to play on turn 3, but come turn 5-6, it has the ability to be a game changer, whether you're flashing back an important early game spell, or using the Harmonize ability to cast an expensive spell at a reduced rate
(7/15/2006) The last ability is now a triggered ability, not a replacement effect
(2025-06-06) You can cast a spell using flashback even if it was somehow put into your graveyard without having been cast