Thats nice, but it also puts a +1/+1 counter on any nontoken creatures that enter the battlefield under your control, and lets you draw a card when you do so
Gaston has shift 4, but the deck doesn't include a low-cost Gaston (the 2-cost Gaston is Ruby) to allow you to cheat him out that quickly like the Queen, but he can be played on top of the 3-cost Gaston Baritone Bully
That's the main reason we're not dealing with exact figures here, just a straightforward list of very good cards
See rule 702.73, Changeling. 702.73a: Changeling is a characteristic-defining ability
Illuminor Szeras Its possible to make some silly amounts of black mana with Illuminor Szeras, but you only ever get back the same amount of mana you put in unless you make your creatures cost less
You can buy a moderately played version right now for $79k