Can it be said that the release of GPT 5.6 has officially opened the prelude to the price war of cutting-edge closed source large models? Why do you say that? Let's first take a look at the pricing structure of GPT 5.6 (API per million tokens, short context standard price): 1) Sol (flagship): $5 input/$30 output (at the same price as GPT-5.5 flagship). 2) Terra: $2.50/$15 (with performance similar to GPT-5.5 but lower cost). 3) Luna: $1/$6 (cheapest, still strong in performance, close to or surpassing some previous flagships). This is the first time OpenAI has introduced clear multi-layer pricing in its flagship series, allowing users to flexibly choose based on task complexity. Luna and Terra offer the option of "approaching flagship performance but significantly reducing costs," which is highly attractive to developers and API heavy users, directly impacting competitors such as Anthropic's Claude series. Previously, there have been reports that OpenAI is considering a significant price reduction to cope with competition from companies such as Anthropic. This time, through the tiered model, it has achieved "more capabilities at the same price+low-cost high-performance options", essentially responding to the market's demand for cost sensitivity. At the same time, a new prompt caching mechanism (cache write 1.25x, etc.) and multi-agent functionality will be introduced to further enhance the cost-effectiveness of practical use. Of course, it is not a traditional "price war" because the price of the top flagship Sol has not decreased, but is "stronger at the same price". This is more like a manifestation of value war and differentiated competition: OpenAI uses a layered model and Agenetic capabilities (multi-agent, Work agent) to seize the market, rather than simply competing for low prices. More precisely, it is the acceleration of the "cost-effectiveness war/tiered pricing competition" rather than a simple flagship price reduction war. The overall trend in the industry is similar - each company (Anthropic, Google, xAI, etc.) is optimizing pricing structures, introducing tier models, and Agent functionality. OpenAI's move is likely to accelerate this process, especially in terms of API pricing and agent capability competition for closed source frontier models. This marks a shift in top-level closed source large models from "single flagship high price" to multi-layer model cost-effectiveness competition+agentic functional warfare. Price sensitive users will benefit significantly and industry competition will become more intense, but in the short term, there may not be a significant drop in prices for flagship models. In the long run, this is beneficial for the entire ecosystem (especially developers), driving faster model iteration and wider application. This article is sponsored by @ bitget_zh, titled 'Bitget Buying US Stocks: Instant Entry, Smooth Trading'