Okay so this is pretty cool, but everyone is super rich forever
My suggestion to alleviate the holy stuff so much money factor is twofold: Commodities and Upkeep costs.
Upkeep would be paid on events. For every evented brick you have, you pay a base of $1 + $0.10 per event on it rounded down; so a brick with up to 9 events is $1, but 10+ is $2, etc, etc.
Doors would be exempted from this if they have only one event.
Commodities would be certain luxuries, such as vehicles, and would be quite expensive; after all, driving around is fun and allows people who already have loads of money to continue enjoying themselves by being a nuisance to others by getting their cars stuck in things. Wonderment! You could restrict vehicle spawning to only allow you to spawn vehicles you have purchased. Another possibility would be restricting customizing your appearance, and allowing people to sell clothing, but that might be both overreaching and against your ~creative vision~ so whatever.
Right now you get income from your bricks and your banked money, and ticks are quite fast, thus everyone who does anything at all gets rich very fast and there's nothing to really spend your money on aside from more bricks - and I don't build fast enough to outpace my income now.