4 Pokmon TCG booster packs (Each Sun & Moon Series booster pack contains 10 cards and 1 basic Energy Each XY Series booster pack includes 10 cards.)
The Latcher on it's own makes for an excellent minimalist wallet with a very small footprint
If you want the strongest deck right out of the box, the community agrees, theCounter Blitz deck, led by Tidus, Yunas Guardian, is the winner
Id also never go below four copies of Darksteel Citadel because it plays a big role in some of your nut draws
This leads us to a max of about 12 non-engine slots in a 40 card deck (scalable up to about 18 non-engine in a 60 card deck) *
When Kardur, Doomscourge enters, until your next turn, creatures your opponents control attack each combat if able and attack a player other than you if able