I seriously considered buying an XBone for Killer Instinct.
Ultra kooooombooooooo
Killer Instinct is the game I was most interested in too, shame it turned out to be Free 2 Play bullshit.
Looks like the $40 thing is for season 2.
"The $40 bundle will net you all 8 characters, everything included in the aforementioned version, completely different skins that will pay homage to their original Killer Instinct counterparts and a download for the first Killier Instinct title. "
Source
I only skimmed though so might be wrong. Still, super bummed they won't just release the damn game.
To be fair KI is really fun (or it was, the recent couple of patches have apparently broken the multiplayer because lol Double Helix). It's not really F2P, the base game is just a demo where they give you a different character each month. Like at first you could only play as Jago, whereas this month he's been locked and you can only play as Spinal. If you buy the full thing you get all the characters and whatever else they decide to add for the time being.