You can have only 1 face-up "Gravekeeper's Chief" on your side of the field at any time. As long as this card remains face-up on the field, your Graveyard is not affected by "Necrovalley". When you Tribute Summon this monster, you can Special Summon 1 monster that includes "Gravekeeper's" in its card name from your Graveyard.
Near Mint / Lightly Played Unlimited - $1.00
Moderately Played Unlimited - $1.00
Heavily Played Unlimited - $1.00
Damaged Unlimited - $1.00
Near Mint / Lightly Played 1st Edition - $4.50
Moderately Played 1st Edition - $4.50
Heavily Played 1st Edition - $3.50
Damaged 1st Edition - $3.00