The ability being dependent on the power of the cards just makes this scalable, and Im sure there is an infinite attack combo in there somewhere that helps get around fog effects
Of those which were handed out, only ten have been graded by the PSA, with just six of them achieving the coveted PSA GEM-MT 10 rating
But because historic permanents are so common, this card will likely end up being pretty cheap to play
As a starter Pokemon this card wouldn't be useful because it can't attack for three turns, at least do damage that is, and if you use Nap each turn until you get three energy cards, doing 30 damage a turn with Razor Leaf won't do much against a stage 1 or a stage 2 Pokemon
And while Mercurium has material, your opponent cannot activate any monster effects in their Graveyard, if you have a monster with that same Attribute in YOUR Graveyard