OpenAI and Anthropic slash prices in aggressive push against open source AI models

The AI pricing war just entered a new phase. OpenAI and Anthropic have been systematically slashing prices on their mid-tier models throughout 2026, with reductions steep enough to make developers reconsider whether open source alternatives are still worth the hassle of self-hosting. The numbers behind the price war On July 30, OpenAI cut prices on GPT-5.6 Luna by 80%, bringing costs down to $0.20 per million input tokens and $1.20 per million output tokens. The company’s higher-end GPT-5.6 Terra also got a haircut, dropping 20% to $2 input and $12 output per million tokens. Anthropic followed on August 10, making the introductory pricing for Claude Sonnet 5 permanent at $2/$10 per million tokens. Then September 22 brought a second wave. OpenAI launched GPT-6 Sol and Luna at $2/$10 and $0.10/$0.50 respectively, roughly 50% lower than previous generation pricing. Anthropic countered with Claude Opus 5.5 at $4/$20 list pricing, though built-in efficiency improvements deliver around 40% effective savings for users. Why open source is feeling the squeeze Enterprises are increasingly splitting their workloads into tiers. Cheap proprietary models handle routine tasks like summarization, ...