A SaaS founder forwarded us a vendor invoice with one comment: "this is 6.4 times what they projected." The system was a "multi-agent crew" that a consultancy had pitched as the upgrade from his single-agent customer support chatbot. The pitch had projected $0.04 per query. Production was running at $0.255.
The accuracy lift over the previous single-agent setup was 4 percentage points (from 78% to 82%) on the team's eval set. The latency had gone from 4 seconds to 19 seconds at the 95th percentile. Customer satisfaction had dropped because users were giving up before the response arrived.
The diagnosis was that the system did not need most of the agents the vendor had built. Multi-agent is a real and useful pattern. It is also frequently the wrong tool for the job, sold to teams who do not have the framework to push back. Here is the math we walk founders through.
The actual cost multiplier
A single-agent system handling a customer query costs roughly:
