Say you’ve got the free tier and the premium tier, and then another premium tier that adds even more rewards, such as maybe a 30$ tier that gives you double the amount of mutated dungeon runs.
Look, I’ll pay a full MMO subscription price of 15 - 20usd a month to unlock the silly caps on mutated dungeon runs. And, I’m sure a lot of other people would pay a subscription to get rid of the “free to play” limit model.