Caveat emptor
You'd think the models would have a better billing experience...or maybe not. Insidiously, Claude wasn't very helpful when I tried to figure out what was driving my bill. Gemini was very quick to correctly identify the issue. Go figure. Just make sure you have "Usage Limits" turned off (Settings > Usage). Even with a monthly spend limit set, you'll be surprised by your bill. The meter keeps running with no warning in Claude Code when you hit your plan limit. Sure, an opaque billing system means more overage and more revenue for Anthropic...but come on now.