Unlike the previous two cards, Swords to Plowshares costs well below $1, but its without a doubt the most popular card included in Fourth Edition
The Ten Most Expensive Cards From Phyrexia: All Will Be One - Insane Prices
That said, Eldrazi Displacer has been an incredibly impressive card in all formats, and its a card I like having in my deck against G/W Tokens specifically
The biggest downfall here is it doesnt create any card advantage
Shatterskull Smashing / Shatterskull, the Hammer Pass Shatterskull Smashing isnt an incredible rate on a fireball, but its worth the opportunity cost of running a card that, at its absolute worst, is just a tapped Mountain
Keep in mind that this isnt a list of the best discard effects in MTG