Because you can't put a price on happiness
Ratchet BombRatchet Bomb and Engineered ExplosivesEngineered Explosives are handy sweepers, and can be played for extra layers of value in this deck since their charge counters will become +1/+1 counters after sacrificing them
Shopkeepers Bane What would you get if you took a Charging Badger and two Pest tokens (the ones with attack triggers), and put them in a super-Frankenstein-blend-o-matic
Oh yeah, before getting into it, there's one other aspect of Secret Lairs that we need to touch on briefly: the stained-glass planeswalkers
The Fantasticar though ostensibly a Commander card is seeing interest primarily for Legacy and Vintage, though, given you can chain all manner of cheap mana rocks that are either free or cost one mana
The basic idea is that a flashlight on full blast will cut through a legit card and show through on the other side, while a counterfeit card will either block the light completely or dull it significantly