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 - $19.50
Near Mint Non-English - $19.50
Lightly Played - $18.50
Lightly Played Non-English - $18.50
Moderately Played - $15.50
Moderately Played Non-English - $15.50
Heavily Played - $11.75
Heavily Played Non-English - $11.75
Damaged - $9.75
Damaged Non-English - $9.75