I am a Champion!
What a day! At the start of yesterday, I was in the Bronze I league. By the end of the day, I'd made it to the Diamond League. This morning, I made it to Champion III! My card rentals are less than $2 a day, too. That's really not that bad, considering how far I can make it. While I think it'll cost more than it brings in, it won't be by that much, and I mostly play because it's fun. If I wanted to earn money, there are much better things I could spend my time doing.
I got some pretty decent quest rewards, too!