My AI Bill Was $0 in January. By March It Was $150. Here's What Happened.

January was easy. I barely used any AI tools. Claude was a curiosity, not a dependency. My Anthropic bill: $0. By March, I was building two macOS apps as a solo dev. Claude was open in one window, Cursor in another. I barely thought about the cost — I was moving fast, shipping features, feeling productive. Then I opened my billing page. $150. In one month. I sat with that number for a second. It wasn't catastrophic, but it was real. And the thing is, I had no idea