The Hidden Math Behind AI Agents: Why GPT-4o Can Be More Expensive Than Hiring a Human

TL;DR: I built a free calculator that models the true cost of AI autonomous agents vs. human VAs — and the results surprised me. If you're building with LLM APIs in 2026, you've probably celebrated how cheap inference has become. GPT-4o Mini at $0.15/1M tokens. DeepSeek V3 at $0.14/1M tokens. It feels almost free. Until you run an autonomous agent loop. Then the math breaks in ways nobody warned you about. The Problem: Context Windows Are Cost Multipliers In a standard API call, you send a promp