Cube is a slower format, so Milotic from Dragons Exalted (#28) is insanely good, especially if you're playing a good Ace Spec like Life Dew or Rock Guard
Here are a few examples that wont totally break the bank: Japanese Pokmon 151 Mew EX, an Ultra Rare card valued at around $130 Japanese Triplet Beat Mewoscarada, a Special Art Rare for around $70 Japanese Duraldon V, a Super Rare card valued at $11.06 As you can see, Japanese cards can vary wildly in the Western market
Together with Yawgmoth, Thran Physician and Blood Artist, Young Wolf makes for a repeatable combo that allows you to drain an opponent of all of their remaining life
Xerneas ex XY Base Set (Full Art, 146/146) Representing one of Kaloss legendary mascots, this card remains surprisingly cheap, considering its playability and stunning rainbow-backed illustration
Seriously though, a good, cheap sacrifice outlet in Green isnt the easiest thing to come by
Arita is a legend in Pokemon TCG, having illustrated many of the game's most iconic cards