GPT-5.6’s three tiers create a 5x cost spread on identical workloads, and the default alias quietly bills at the priciest one. Here’s what Sol, Terra, and Luna actually cost, how caching cuts the bill, and why OpenAI’s own system card makes this a governance question for finance, not just a pricing one. The post GPT-5.6 pricing: Sol, Terra, and Luna costs appeared first on CloudZero .