Baba Is Solved by Fable 5 and GPT-5.6 Sol, but at what cost?

GPT-5.6 Sol and Claude Fable 5 solved almost all levels in the first two stages of Baba Is You, but took significantly longer and cost more than humans. The researchers spent over $2000 on experiments, finding that cheaper models like Gemini 3.5 Flash were sometimes more expensive than Fable 5.