The difference is that while they have an ink cost on them, there is also an extra block of text in the description area of the card which details that you can exert a character (turning them sideways and opening them to attack) of a minimum cost in order to play the song card for free
Chart shows the price of Zenos yae Galvus [Extended Art Foil] #455 at the end of each month going back as long as we have tracked the item.
It also helps to include a good number of cards (at least 45 out of 60) that can be added to the Inkwell denoted by the golden circle around their cost
Legendary creatures you control get +2/+2.
Powerful reprints, returning legends, and four ready-to-play decks bring Commander Masters to life on August 4, 2023
While I've talked about which cards I think will make an impact on the Control archetype, here are the other cards I think may or may not make an impact on the format, as the set is legal until 2028