Draconic Domination

Draconic Domination is a 100-card Commander precon from Commander 2017, released August 25, 2017. It is led by The Ur-Dragon, a five-color commander.

The Ur-Dragon

Eminence — As long as The Ur-Dragon is in the command zone or on the battlefield, other Dragon spells you cast cost less to cast.
Flying
Whenever one or more Dragons you control attack, draw that many cards, then you may put a permanent card from your hand onto the battlefield.

The list runs 37 lands and 32 creatures, and its nonland cards average 4.37 mana. At today's TCGplayer prices the whole deck's cards come to about $169.41, and the most valuable is The Ur-Dragon at $37.34.