Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)
Near Mint - $12.90
Lightly Played - $10.30
Moderately Played - $9.00
Heavily Played - $7.80
Damaged - $6.50
Near Mint Spanish - $12.90
Lightly Played Spanish - $10.30
Moderately Played Spanish - $9.00
Heavily Played Spanish - $7.80
Damaged Spanish - $6.50