Local Large Hobby Shops that hold the official tournaments. They are trustworthy, I mean, even The Pokemon Company trusts them. The more people at the hobby shop for the tournaments, the better. Some of them even have Pokemon booster packs at a lower price. The one I go to sells them for 4 dollars. If you live in Metro Vancouver, you should go to Connection Games and Comics at Metrotown, or Craving for a Game at Central City Mall in Surrey for the best deals. For singles, the best place I can think of is Pasttime Games (which is really close to Craving for a Game), they have a trade - in policy there. For Japanese Cards, there are Japanese hobby stores too ^_^. (Gacha Hobbies, Aberdeen, Richmond, British Columbia)