If you just need an extra copy of a winning card, add a transmute card as a supplement to your more expensive tutor suite is a decent way to get it out of your giant Commander deck
The next expensive card in our list is Transmute Artifact
Of course, it does have the big drawback of letting your opponent draw 2, but situationally this isnt the worst see Prince Johns Mirror below
Its an excellent role-player that creates pockets of potential interaction that didnt exist before, allowing more midrange and control decks to interact with the opponents in the first few turns when mana constraints would be a severe issue
Utility creatures, offensive creatures, defensive spells, disruption tools, and facilitator spells are the most common playable one-mana options
Dillon Deveney, Principal Narrative Game Designer : I love this question