Starters have an average BST of 313:

Basic Grassmon:
Type: Grass
Ability: Overgrow (Pickup HA)
Stats:
HP - 45
Atk - 73
Def - 45
SpA - 40
SpD - 35
Spe - 75

Basic Firemon:
Type: Fire
Ability: Blaze (Huge Power HA)
Stats:
HP - 50
Atk - 55
Def - 50
SpA - 35
SpD - 65
Spe - 58

Basic Watermon:
Type: Water/Poison
Ability: Torrent (Poison Touch HA)
Stats:
HP - 65
Atk - 62
Def - 55
SpA - 40
SpD - 50
Spe - 40