For those already monetizing agents - which model are you using, or what are you considering?

(mostly thinking around 1. Agent-based billing - Fixed fee per agent; 2. Workflow-based billing - Pay for what the agent does; 3. Outcome-based billing - Pay only for successful results)

I'm seeing most start with agent-based but quickly hit limitations when customers want to scale.

Also curious: How are you handling the "but ChatGPT is $20/month" objection when pricing enterprise agents at $30k+?