When I got there, the cards were all laid out on the guy's kitchen table
The Confluence costs a massive six mana and three in colors, but you can goad one player's stuff three times, so it's Disrupt Decorum in a four player game, or you can use it as removal of a -3/-3 nature up to three times, which will kill indestructible stuff and not exile them so you can recur them later or you can Regrowth a sorcery/instant up to three times
ST06-015 Great Eruption While many other cards reduce cost in a way similar to this card, this is the only card that can reduce cost without consuming any cards in the players hand or imposing any conditions, making it powerful in every stage of the game
At the very least, with a Golgari color identity, its five defense counters might just be worth cracking to gain access to a Beanstalk Giant clone
I believe that three is the minimum, but there are arguments to be made on why to include a full playset
Japanese booster boxes are easier to import reliably and often remain at a more stable price point