(I should also mention that this doesn't include reprints, so fetch lands are counted as Zendikar cards, not Modern Horizons 2 cards, so they aren't skewing the data.) While Modern Horizons sets add a lot of interesting new cards to the Modern format, at this point, it's clear that they also add a lot of expensive cards into the Modern format, which in turn ends up increasing the cost of playing the format
even classic commanders like Meren of Clan Nel Toth and Atraxa, Praetors Voice want to be down as soon as possible, too
It does include free shipping after all
Compare that to Dragon Vault at 21 cards and its not hard to see why the number of cards available is growing quicker and quicker
I don't feel confident about other formats - but Gisela will certainly find a competitive home in Standard
It's a standard for Sliver decks, but since it hasn't seen too many reprints, demand has bumped the price of Crystalline Sliver up a slice or two