Raging Battle Mouse's cost-reduction ability doesn't change the mana cost or mana value of any spell
Protect your card High Chase Score protect and consider grading
More times than not you will probably grab a creature, but in landfall decks, a card like Fabled Passage may be beneficial
Edit: realized this was for rares, but hopefully yall can make an exception
For newer collectors, its a focused, achievable set that wont require chasing hundreds of cards
If a face-up Insect, Plant, or Reptile monster(s) you control is destroyed by battle or card effect, while this card is in your GY, except the turn it was sent there: You can banish this card, then target 1 monster your opponent controls