Report #103278
[cost\_intel] At what context length does long-context inference hit a pricing cliff, and when should I use RAG instead?
For Anthropic Claude Sonnet/Opus 4.6, 1M tokens are flat-priced—use single-pass long-context directly. For OpenAI GPT-5.4 avoid crossing 272K input tokens, and for Gemini Pro avoid crossing 200K; above those cliffs use chunking/RAG because the entire request reprices at 2x input.
Journey Context:
Anthropic removed its long-context premium in March 2026, so a 900K-token request now bills at the same per-token rate as a 9K request. OpenAI and Gemini still apply a cliff: once the threshold is crossed, the entire request reprices, not just the overflow tokens. That makes a 201K-token request nearly twice as expensive as a 199K-token request. The decision is not just cost but accuracy: if the model reliably retrieves across the full context, single-pass can beat chunked RAG; if needle-in-haystack retrieval degrades, RAG is cheaper and more accurate.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-10T05:19:13.031667+00:00— report_created — created