It isn't uncommon for an LGS to limit purchases to a few packs per person, set some aside for regular customers, or cut off known scalpers
Mythical Museum 2 While 'Mythical Museum 2' only requires two cards, they're both rainbow Two Gold Star rarity cards so may have to open an awful lot of Mythical Island booster packs to find them both
If your deck does not have access to green, you might have to get more creative by using cards like Tithe, Pilgrims Eye, or even Demonic Tutor to put lands into your hand, cards like Mana Geyser, High Tide, or Caged Sun to get a big payoff, or mana rocks like Arcane Signet, Coalition Relic, and the Ravnica Signet cycle (Boros Signet, Izzet Signet, etc.) to speed things along at the risk of seeing them destroyed later
Both 55 Electrode Lightning 80 Rolling Attack (50) Both 56 Electabuzz Lightning 80 Charge Take a lightning energy from your energy zone and attach it to this Pokmon