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.)
NM-Mint - £7.40
NM-Mint Non English - £7.40
Lightly Played - £7.00
Lightly Played Non English - £7.00
Moderately Played - £6.30
Moderately Played Non English - £6.30
Heavily Played - £5.60
Heavily Played Non English - £5.60
Damaged - £4.50
Damaged Non English - £4.50