One the Card Creation forum, I posted
this card:Read 'Em & Weep

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Sorcery
Draw a card.
If an opponent would mulligan, you may reveal Read 'Em & Weep from your hand. If you do, opponent can't mulligan during this game.The response was a unanimous, "What a terrible idea- in principle, that's just
really bad for the game!" I've given it some thought and, OK, point taken. Here's another card that's really bad for the game:
MTG Sux Now- Let's Play Hold 'Em!

Instant
Flip a coin. If you win the flip, you win the game.However...Let's say each card existed, and the format was Vintage, and I needed the tournament prize to pay for mother's kidney surgery. I'd most certainly run 4 MTG Sux, and so would you. But would you run Read 'Em and Weep? It's useful only if they Mulligan, and then there's a 60% chance it isn't in your hand anyway.
What if it cost


?