
What GPT-6.1 Terra Really Costs: Effort Levels, the 272K Line, and Caching
GPT-6.1 Terra launched on 26 October 2026 at $1 per million input tokens and $5 per million output tokens, half of GPT-5.6 Terra's input price and well under half of its $12 output price. The list price is only the starting point. Three things decide what a Terra workload actually bills: * Reasoning effort. Reasoning tokens bill as output, and the gap between effort levels is several-fold. * The 272K line. Once a request's input crosses 272,000 tokens, the whole request moves to a higher rat








