One is to focus on the fact that for most Secret Lairs , you really aren't getting a big discount by buying them directly from Wizards compared to buying them on the secondary market a couple of months after they are released, so you're probably best off waiting and just picking up specific cards you want as singles, especially if you don't really care about all of the cards in a drop and just want one or two
Most valuable cards in Majestic Dawn View the full price guide More cards by Ryo Ueda Discover
A staple in most decks as you pick it up with an Itemfinder from base set (a very flexible card), and use the card again if need be, thus only needing one per deck
Jodah, Archmage EternalJodah, Archmage Eternal allows us to cast Kozilek for the much more palatable cost of WUBRG
That might be it, and going from 5 DON
This field card would grant its user the ability to use its spell and trap zones to summon monsters