Done-for-you custom agent builds: $5K–$15K per project plus a monthly retainer
Freelancers and small agencies charge $5,000–$15,000 to build a custom AI agent for a mid-market business, then $500–$2,000 a month to maintain it — updating prompts when models change, fixing edge cases, and monitoring runs. The real money is the retainer, not the one-off build, and the bottleneck is the sales cycle, not delivery. Prices and creator examples are self-reported.