The Aetherspark (Serial Numbered) - $1,650 Aetherdrift might not live long in the memory for many, but The Aetherspark is a very, very cool card - especially if you have one of the 500 serialized versions
G - Leafage 10 Dartrix C - United Wings 20x This attack does 20 damage for each Pokmon in your discard pile that has the United Wings attack
(Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.) Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.) Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.) Artifact - Vehicle The Aetherspark As long as The Aetherspark is attached to a creature, The Aetherspark can't be attacked and has "Whenever equipped creature deals combat damage during your turn, put that many loyalty counters on The Aetherspark." +1: Attach The Aetherspark to up to one target creature you control
But it did go well, quickly becoming the talk of the show and immediately being put on the schedule for the next MagicCon, and then growing into one of their marquee draws ever since
Other cheap (price-wise) examples would be Pilfer, Concealing Curtains // Revealing Eye, Dread Fugue, Distress, etc