These days, Commanders are chock full of value for far less than five mana
Kaldheim brings with it new keywords such as Foretell, which allows you to exile cards from your hand to play them later for slightly cheaper, and Boast - which is a lot like the Raid mechanic from Tarkir, but this time around you can use special effects on cards for a different cost
It's a 1/1 in terms of Strength and Willpower, and it only quests for one lore
15 Jin-Gitaxias, Progress Tyrant Jin-Gitaxias, Progress Tyrant is the second iteration of the blue Praetor of New Phyrexia and is a powerful albeit mana-intensive commander option
You cant break down cards to craft new ones or trade at all, which means youre stuck with whatever you get
In fact, you can consider lands that enter the battlefield tapped as giving you more flexibility in how you build your mana curve