Not actually advocating this, but if you wanted to show them something really exotic, Manaless Dredge is about $60 (without sideboard) according to TCGPlayer.
It is a deck that plays no lands, starts the game by doing nothing for a turn, then discarding at end of turn for having too many cards in hand, then very quickly dumps the whole deck into the graveyard and its creatures keep coming back from the dead. A video showing it in action is here https://www.youtube.com/watch?v=Yw9J-n4nw2Y

The downsides are
1) It's not very fun to play against, because your turns take forever and then they are suddenly dead
2) The cards are completely useless in any other deck
3) It plays basically the same every game, so it's not even that fun for the pilot after a while :-)