At some point, you should stop gaining power altogether, and only get symbolic fluff. People will look at you and whisper: "Wow... you're a legendary tax payer? That must have taken a lot of grinding."

Earning profit should be like leveling. It's fast and easy to get going, but of course there's diminishing returns at the top. Getting from 99 million to 100 should be a titanic effort.

Climb into the high tax brackets, you start earning vanity items that can't be bought with real-world currency. Account-bound cloaks, special emotes and rare decorations for your mount.