GPT-5.6 Pricing Breakdown: What the API Really Costs to Run
OpenAI lists GPT-5.6 at $5/$30 for Sol, $2.50/$15 for Terra, and $1/$6 for Luna per million tokens — but almost nobody running production should pay list. Prompt caching cuts repeated input to a tenth of sticker and Batch mode halves the rest, dropping a realistic workload roughly 48% below the naive bill. Once discounts are in play, the fight with Claude Sonnet 5's $2/$10 intro pricing and Gemini 3.1 Pro's $2/$12 is closer than the stickers suggest. For PMs, the takeaway is that model cost is now an architecture decision, not a procurement one.
