For the Charizard 1st Edition Shadowless, only about 120 copies have achieved the perfect PSA 10 grade out of the thousands submitted
You cast Demonic Consultation and name any card that you know isn't in your library (for this deck, might I recommend Forest?) Then, when your entire library is exiled, just play Thoracle from your hand and bada-bing, you win
If they want to win more, they'd run more Land, hit more drops, spend more mana, cast more spells, and win more games
What is the pull rate for Mimikyu
If you want to dig further into calculating EV for a specific box, you can utilize resources like MTGStocks or check out the youtube video below, which does a great job of explaining a few other details you may want to consider when calculating expected value
Elesh Norn, Mother of Machines, for instance, is worth roughly $27 at the moment