Zamakliike, Phyrexia's Marvel

At the beginning of your upkeep pay {3},
or sacrifice this creature.
If you control fewer than 10 artifact creatures
this card is not a creature and becomes a land in addition to it's other types.
{1}{b}{u}{w} {t}: add {x} colorless mana to your
mana pool equal to the highest converted mana
cost among artifact creatures you control.