Talk:Heimerdinger/@comment-168.8.249.173-20130201192310/@comment-5052127-20130213131829

Mana costs affect the early game the most, his are meant to try and limit his power early my making it so that he cannot sustain very strong harass using his abilities.

You usually see high mana costs on champs that have very long range or very reliable harass in lane, and his rockets hit automatically in lane, so the extreme mana cost is there to make sure that he can't sit there forever and hit you with his rockets every time the cooldown is up, unless he does something to get extra mana.