PSA 9 cards usually command only 30-50% of a PSA 10's valuea massive drop-off for just one grade point
Slash of Light might find value in Standard or even fringe Modern decks due to its cheap cost
Mime (LV 28) 1x Jynx (LV 23) 1x Mew (LV 23) 2x Pidgey (LV 8) 1x Pidgeotto (LV 36) 1x Pidgeot (LV 40) 2x Rattata (LV 9) 1x Raticate (LV 41) Trainer: 1x Professor Oak 2x Bill 1x Switch 1x Gust of Wind 2x Potion 1x Full Heal ------------ Water Beetle ------------ Description: An evolution deck with Weedle, Nidoran (M), and Bellsprout
The triggered ability helps ensure you always have a creature to play and such an effect is the lifeblood of many green decks
Individual packs, on the other hand, have routinely sold for $5 each
With that said, for me this list begins with Aethersquall AncientAethersquall Ancient, which while expensive, is the threat that I have seen win energy decks the game time and time again