You may choose not to untap Amber Prison during your untap step. {4}, {T}: Tap target artifact, creature, or land. That permanent doesn't untap during its controller's untap step for as long as Amber Prison remains tapped.
Near Mint - $1.25
Lightly Played - $1.25
Moderately Played - $1.25
Heavily Played - $1.25
Damaged - $1.25
Near Mint Spanish - $1.25
Lightly Played Spanish - $1.25
Moderately Played Spanish - $1.25
Heavily Played Spanish - $1.25
Damaged Spanish - $1.25