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 - $23.70
Lightly Played - $19.00
Moderately Played - $16.60
Heavily Played - $14.30
Damaged - $11.90
Near Mint Spanish - $23.70
Lightly Played Spanish - $19.00
Moderately Played Spanish - $16.60
Heavily Played Spanish - $14.30
Damaged Spanish - $11.90