When a Spell Card, Trap Card, or monster effect is activated, while both a "Gravekeeper's" monster and "Necrovalley" are on the field: Negate the activation, and if you do, destroy it. You can only activate 1 "Imperial Tombs of Necrovalley" per turn.
Near Mint Unlimited - $0.90
Near Mint 1st Edition - $1.90
Lightly Played Unlimited - $0.80
Lightly Played 1st Edition - $1.80
Moderately Played Unlimited - $0.70
Moderately Played 1st Edition - $1.60
Played Unlimited - $0.60
Played 1st Edition - $1.20