As @milhouse said, no cards of Zygarde or Volcanion are out yet. Honestly, just go to Troll and Toad or any singles website and buy all the cards you need. It’ll take time, but it’ll be the most cost effective.
Im not going for 721, I’m getting complete collections of my 2 favorite 'mons and just collecting whatever is cool after that. Not too into collecting sets just have my eyes on Southern Islands.
Trying to convince yourself ay? Thats what I said. “Only Charizard”,“only the trio” “only 150 pokemon” hah yeah right 1000+ cards later im still trying to convince myself.
You won’t find cards that cheap. Even people who sell bulk on Ebay sell them for 5 cents to 10 cents each. I sell some of mine at a quarter each (and lose money), because I buy most of the packs at retail. The one positive of weighing packs. Also trollandtoad buys bulk commons/uncommons at 5.5 cents each.