Counter target spell unless its controller pays {X}. If that player doesn't, they tap all lands with mana abilities they control and lose all unspent mana.
Near Mint - £50.50
Lightly Played - £43.00
Moderately Played - £35.40
Heavily Played - £25.30
Damaged - £15.20
Near Mint Non English - £50.50
Lightly Played Non English - £43.00
Moderately Played Non English - £35.40
Heavily Played Non English - £25.30
Damaged Non English - £15.20