I think the pricing model is great. Realistically most people only main one or two characters if you apply that to KI. The total cost of the game is 10$.
The other great thing about the pricing model is that the base game is free. Which means it's accessible to new players, I don't have to say hey man take my word for it you'll really like MK9 just go drop 60$ on it so we can play together. Instead he/she can go check out KI for free and decide if they want to spend money on it.