Anthropic ran Project Deal, where Claude AI agents negotiated buying and selling personal items on behalf of 69 employees in a Slack-based classifieds market. They compared outcomes between a top-tier model (Opus 4.5) and a smaller one (Haiku 4.5), finding that smarter agents secured higher prices and more deals—differences participants didn’t notice. In total, agents struck 186 deals worth just over $4,000.

• Anthropic had 69 employees delegate real negotiations to Claude agents, resulting in 186 deals worth about $4,000 in a week.
• Agents running Opus 4.5 closed roughly two more deals and got better prices than those running Haiku 4.5, despite identical budgets and rules.
• Haiku users didn't notice they were getting worse outcomes, rating their results as fair anyway—exposing a gap between perceived and actual performance.
• This hints at a near-future where the AI model you choose quietly determines who wins in everyday automated commerce.