It’s the legal maximum fine for this, and there are still three other charges that will be discussed this week. It’s very much possible that Trump may see the inside of a jail cell, but that remains to be seen.
And even though it seems like a tiny slap on Trump's tiny wrist, it's still an escalation. So next time Trump flagrantly violates gag orders the judge can escalate more. If there's an appeal it'll be important to be able to show the judge didn't jump straight to the harshest penalties.
His stake in his "media" company is (nonsensically) still worth billions of dollars right now. He probably won't be able to cash all of that out if he wanted to, but he is definitely not broke.