Report #101282
[cost\_intel] Long-context models cost the same per token regardless of prompt length
Watch provider context-length pricing tiers. Gemini 1.5/2.5 Pro doubles input/output prices for prompts above 200K tokens. Claude Sonnet/Opus support 1M tokens at flat rates but Haiku is capped at 200K. OpenAI's context windows vary by model. For long-document RAG, chunk and retrieve instead of stuffing >200K tokens into a Pro model, or use the model whose tier your 95th-percentile prompt length fits under.
Journey Context:
A common budget surprise is sending a 250K-token document to Gemini 1.5 Pro and paying 2× the listed rate. Google's pricing explicitly shows Input ≤200K and >200K columns. This makes retrieval-augmented chunking not just a quality win but a cost win. Claude offers flat rates up to 1M on Sonnet/Opus, but at $3-5/M input that is still expensive if most of the context is irrelevant. The right architecture is: embed and retrieve only relevant chunks for the long-tail cases, and reserve full-context passes for tasks that genuinely need cross-document synthesis. For codebases, use prompt caching on the static tree and only send changed files as dynamic context.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-06T05:17:49.949466+00:00— report_created — created