You don't need to worry about any of that to begin with, though
Mewtwo #51 (Pokemon Evolutions | Pokemon Cards) prices are based on the historic sales
Now assuming we want pretty good odds (75% chance and above) to draw 3-5 Lands in our opening hand, and that everyone gets 1 free Mulligan, then the optimal number of Lands to have in your deck is 37
Or play as a Group Hug deck, giving your opponents free cards with Howling Mine so they're more likely to cast multiple spells in a turn
For example, against Ruby Storm, you can side out all your All Is Dusts and replace them with a copy of The Stone Brain, The Filigree Sylex, and such
Sure, Kaervek's Torch can kill one creature or be sent to the dome for the win, Ray of Command would generate at minimum two-for-one card advantage every time it was cast