There will always be one player at the table who most threatens your life total, and most lifegain decks also want to keep life high for the likes of Aetherflux Reservoir or game-winning triggers
Im always going to wait, Fatal Push a cost reducer if they cast one or Opt if they dont, and Thoughtseize after they spend another turn cantripping to maximize my odds of hitting a Gifts Ungiven or ruining their setup
It even has some decent graveyard hate attached to it as well
With social media purchases, make sure you always ask for references when working with someone new, and trust your gut (if a deal seems too good to be true, it probably is), and you should be fine
What affects the value of Despark
You get your Banishing Light effect for slightly more mana, but you also get a white mana rock to help make up the difference