I've had several games (As Regulus, playing the demo) where I rank easily 1st place, in damage, gold, as well as minions and structure damage dealt. However, I have also encountered, in these games, players who play as Rook, and are nigh impossible to kill.
For example, in a match earlier today, I had Regulus at level 20, as well as a lvl 20 Vampire guy (forget his name) and another lvl 20 Regulus. A SINGLE enemy Rook took our base, simply because while we were all shooting full-bore at him, he simply had bought several health potions. As such, after about 10 minutes of CONTINUOUS fire, he simply ran out of potions, and had to retreat. His teamates then came in to save him.
However, in the time that he spent attacking our base, he destroyed 6 dark towers, as well as 2 archer towers, in addition to all the minion troops thrown at him. His teammates were also busy attacking the other areas of our base.
It seems to me that the health potions need a NERF---they are too cheap for their power, and therefore can render a player almost invincible and not bankrupt. This completely unbalanced the game (I tried it myself, got 16 kills and no deaths, swamped the base almost by myself) and I believe that modifying the HP potions would not destabilize the game balance.
IMO, a price of 1000 Gold would be appropriate (approximately) for the major HP potion. Thank you for reading that rant. 