It will interact better with future cards who may have slightly different themes
If your deck does not have access to green, you might have to get more creative by using cards like Tithe, Pilgrims Eye, or even Demonic Tutor to put lands into your hand, cards like Mana Geyser, High Tide, or Caged Sun to get a big payoff, or mana rocks like Arcane Signet, Coalition Relic, and the Ravnica Signet cycle (Boros Signet, Izzet Signet, etc.) to speed things along at the risk of seeing them destroyed later
The first ability will resolve, and you'll put a +1/+1 counter on Sharp-Eyed Rookie and investigate
Magic: The Gathering has lots of interesting ways to make spells cost more than you think they do
Even though theres been some vampires with white in their colors, we mostly owe this to the Commander 2017 vampire precon
Some people like to buy cards and then never sell them, and down that path lies madness and storage units and lots of cobwebs covering mildewed boxes