While this is already a handy use of two mana, whenever a dragon enters the battlefield under its owner's control, that player can deal X damage to any target where X is the number of dragons they control
Infinite Forbidden might change that with Mulcharmy Purulia, though its restrictions should prevent it from becoming game-breaking
A legal one of either of these bad boys would cost you anywhere from $650 to $800
In the larger world of commander, this also means easier activations on land like Cabal Stronghold, Kessig Wolf Run, Rogues Passage, Gavony Township and the Kamigawa Neon Dynasty channel lands like Boseiju, Who Endures on top of their reductions already, just to name a few
and I assure you, for most of them, you have plenty of options of what deck you can put this in
It should be pretty easy to win the game with so much card advantage